With his brothers Charles and Gustave Frohman, he helped to develop a system of road companies that would tour the nation while the show also played in New York City.

During this period he launched careers for such actors as E. H. Sothern, Henry Miller, William Faversham, Maude Adams, Richard Mansfield and James Keteltas Hackett.

Frohman became involved in the motion picture business as a partner and producer with Adolph Zukor in the Famous Players Film Company.

He worked from offices on West 26th Street in New York City; between 1913 and 1917 he was part of the production of more than seventy films.

[5] He was buried in the Union Field Cemetery in Queens, near his brother Charles, who had died in 1915 in the sinking of the RMS Lusitania.