On graduating from the National Institute of Dramatic Art (NIDA) Rosenthal appeared in several Australian TV shows, including the highly rated Police Rescue, Water Rats, the soap opera Home and Away, and Heartlands, Murder Call and the film The Bet. Rosenthal has recently finished filming The Last Godfather with Harvey Keitel, Jason Mewes and Michael Rispoli.
Rosenthal's most noticeable stage performances were in the world premiere of Louis Nowra's 1998 production of The Jungle, where his character of the Romanian opportunist was said to be 'Streep-like'. The Jungle chronicled the back room dealings of many of Sydney Australia's socialites and notorious underworld dealings and figures from the mid to late 1980s. His other noted performance was as the angry Scotsman 'Brodie' in the 2003 production of Sir Tom Stoppard's The Real Thing, where he played opposite Hugo Weaving at the Sydney Theatre Company.