The four Democratic gubernatorial candidates will meet in Philadelphia to answer a moderator's questions at the annual convention of the Pennsylvania College Democrats.
Friday's two-hour forum at Temple University begins at 7 p.m.
Participating will be state Treasurer Rob McCord, former Clinton White House environmental adviser Katie McGinty, U.S. Rep. Allyson Schwartz and businessman Tom Wolf.
All live in Montgomery County, except for Wolf, who lives in York County.
The winner of the May 20 primary election gets the Democratic Party's nomination to challenge Republican Gov. Tom Corbett in the Nov. 4 election.
The Democratic candidates largely agree on the issues, including expanding Medicaid under the 2010 federal health care law, raising the minimum wage, boosting funding for public schools and raising taxes on the booming natural gas industry.