McNally's 40-plus-year career as a playwright began in 1963 with And Things That Go Bump in the Night. Although the University of Minnesota deemed Bump offensive, presumably for merely depicting gay characters, McNally has suggested that he never saw himself as especially revolutionary. Nevertheless, 1968's Sweet Eros saw a New York first as Sally Kirkland appeared nude for the entire length of the play, and years later McNally drew extensive criticism for Corpus Christi (1999) and its depiction of a gay Jesus Christ and apostles. McNally's first great commercial success was the farcical comedy The Ritz (1974). Other popular works include his two Tony winners for best play: Love! Valour! Compassion! (1994), about a group of eight gay men, and Master Class (1995), about opera singer Maria Callas. McNally also wrote the book for Broadway musical adaptations of Kiss of the Spider Woman (1992), Ragtime (1998), and The Full Monty (2000). His most recent production, Dedication or the Stuff of Dreams, opened August 18, 2005. He has won numerous awards, including four Tonys and an Emmy.

Recalling his time at Columbia College in a 2002 interview, McNally recalled going to theater productions as often as he could; indeed, he camped out overnight for rush tickets on his first night in New York and many times thereafter. “I don’t know how I survived Columbia,” he said. “I went to the theater so much.” In fact, McNally flourished, writing for the Varsity Show and graduating Phi Beta Kappa. He won a fellowship for some work in a creative-writing class that enabled him to travel to Mexico; while there he wrote the script that started him down the path to a professional career in theater.