Mary Del Brady received an intriguing phone call in 1983: The Greater Pittsburgh Chamber of Commerce was launching an initiative to identify potential civic leaders and Ms. Brady, who owned a temporary personnel agency at the time, was among the names mentioned.

The concept was to provide participants firsthand exposure to a broad mix of community sectors -- business, health care, education, nonprofits and government -- and, as Ms. Brady recalled, "to connect us with the people who were really running the city; the movers and shakers of the time."

She and 45 others who entered the first class of Leadership Pittsburgh would gather as early as 6:30 a.m. for breakfast once a month and then embark on a series of site visits to such places as the yet-to-be-opened Light Rail transit line Downtown, where Jim Roddey, then-Port Authority board chairman, led them on an underground tour.

As part of a law and judiciary segment, they met with judges and lunched with inmates at the Allegheny County Jail; and for a session on the pros and cons of local government consolidation, they traveled to the tiny Mon Valley borough of West Homestead.

"We had some pretty healthy debates, and, I might add, we're still having that debate on government and why we still have West Homestead," said Ms. Brady who is now president and chief executive of RedPath Integrated Pathology, a Strip District company that develops tools for cancer diagnostics.

Twenty-five years later, Leadership Pittsburgh still creates a diverse agenda of activities for its classes in an effort to position them for leadership in the public and private sector.

Since the inaugural class of 1983, 1,400 individuals have completed the Leadership Pittsburgh flagship program or one of its affiliates, and a glance through its 25th anniversary directory shows many of them have achieved key roles in which they have helped to shape the region's future.

Ms. Brady's classmates, for instance, included Thomas Usher, who went on to chair U.S. Steel Corp.; Salvatore Sirabella, who became deputy mayor under Mayor Tom Murphy and is now chief of staff for Lt. Gov. Catherine Baker Knoll; Margot Woodwell, former general manager of WQED-TV; and Don Carter, president, Urban Design Associates.

"I was 41 then and it was the best experience I'd had meeting people and having that kind of life-changing experience since college," said Mr. Carter. "We were exposed to the best thinkers in the city."

Members of the third class included Allen Biehler, now secretary of the Pennsylvania Department of Transportation; U.S. Rep. Mike Doyle, D-Forest Hills; Gretchen Haggerty, executive vice president and chief financial officer of U.S. Steel Corp.; Barbara Mistick, director of the Carnegie Library of Pittsburgh; Kathleen Buechel, retired president of the Alcoa Foundation; and Frederick Egler Jr., chief counsel-litigation at PNC Financial Services Group.

Ms. Buechel and Mr. Egler were the first married couple to complete the program simultaneously, said Ms. Buechel, who worked in public affairs for Alcoa at the time and now serves on a number of civic boards including the World Affairs Council, the city's Ethics Hearing Board and the Riverlife Task Force.

"It was a great window on Pittsburgh at the moment," she said. "It was 22 years ago, so computers and Pittsburgh's role in software engineering was just beginning to emerge. We talked about rivers long before there was a Riverlife Task Force. There was the issue of jobs and what would Pittsburgh be and how would it transform itself."

Leadership Pittsburgh traces its beginnings to a group of prominent individuals who were trying to revive the kind of leadership Richard King Mellon and David Lawrence had provided during the city's first Renaissance after World War II, said Doreen Boyce, retired president of the Buhl Foundation.

"Back in 1983, there was a lot of talk in Pittsburgh that we needed new leaders," said Mrs. Boyce who was running the Buhl Foundation at the time and was among what she described as a "group of think tankers" who were "beginning to think we needed to grow the next generation. The steel industry had just collapsed and we needed some new inspiration around here."

After observing leadership programs in Chicago and elsewhere, the group decided to propose a multidisciplinary program that would give participants an understanding of "all the different people who had a stake in the well-being of Pittsburgh," Mrs. Boyce said. "The real up-and-comers from all walks: unions -- and people were terrified of unions then -- people who run the jail, people who run businesses and banks and people in education."

The program operates today much the way it did then: Classes of 40 to 50 people are formed each year from a competitive pool of applicants. The current tuition is $3,950, and the class meets each month from September to June for daylong sessions as well as at least one overnight retreat. Class members take field trips, listen to speakers and panel discussions, and hold their own roundtable sessions on public policy issues.

In a recent day devoted to education, for instance, the current class met with a national expert on education policy and then broke up into small groups to visit eight local public schools where pupils ranged from grades K-12.

"Some were high-performing public schools, some not so high-performing," said Aradhna Dhanda, president and chief executive of Leadership Pittsburgh. "So they got exposure to what is really happening in the schools."

After the site visits, the class reconvened to complete a simulation exercise on how to design an excellent school district.

"It's not like learning something in a conference room or over the Internet," said Ms. Dhanda. "Our philosophy is it has to be experiential."

The organization operated as an arm of the Chamber of Commerce until 1995 when it spun out as an independent nonprofit.

"It needed to grow beyond being a program of the Chamber. It needed more of its own identity in the community … and it became more inclusive in a way," attracting more women and minorities, said Beth Wainwright, a former executive director of Leadership Pittsburgh.

About 500 of the alums are expected to gather Saturday night at the Westin Convention Center Hotel, Downtown, to mark the organization's 25 years. The event will include cocktails, light food and music. But there will be "no speeches, no black ties, no awards," said Ms. Dhanda, a graduate of the 18th class who became president and chief executive of the organization in late 2004. The only formality planned, she said, is to "raise a toast to leadership at 9 p.m."

Earlier in the day, individual classes will hold their own reunions throughout the city at venues including Bossa Nova, Mullaney's Harp & Fiddle, the Duquesne Club and the Engineers Club. "Then we'll come together and have a blast," said Ms. Dhanda, a native of Bhopal, India, who came to Pittsburgh in 1999 and worked previously as executive director of the Children's Festival Chorus of Pittsburgh and a program officer for the Forbes Funds.

Alums such as Ms. Buechel and Mr. Carter believe that Leadership Pittsburgh planted the seeds for their later involvement in nonprofit boards and other community activities.

"It gave me the ability to feel comfortable on almost any board I was on," said Mr. Carter, who has served on the boards of Pittsburgh Public Theater, The Andy Warhol Museum and the Pittsburgh Downtown Partnership.

"I got an even deeper appreciation for nonprofit and civic boards that I carry on to this day," said Ms. Buechel. "Fred [Egler] and I became involved in a number of boards after that. We were young at the time … and it helped us find ways to plug in meaningfully."

But it's tough to document precisely how effective Leadership Pittsburgh has been in grooming future leaders, said Mrs. Boyce.

"I know it has created a network. And who knows what's come out of the network? Clearly it must do something or else who would be willing to spend all that time? One of our objectives was to diminish the insularity, the parochialism of Pittsburgh. My interest was in helping people to broaden their view of what Pittsburgh was all about and what it could be."