In 1987 he served as the film researcher and historian for the "Hollywood and History" costume exhibition at the Los Angeles County Museum of Art. In 1992 he published The Scorsese Picture: The Art and Life of Martin Scorsese. In 1998 he published Open Secret: Gay Hollywood 1927-1997. As he documents on his blog and website, lawyers representing Hollywood actor Tom Cruise threatened to take legal action against Ehrenstein because he wrote of how Cruise is appealing to both men and women.
