He appeared in over 300 credits, notably Spartacus (1960) and One Flew Over the Cuckoo's Nest (1975), during his career spanning over 60 years.

He appeared as Claymare, an Organian council member, in the Star Trek episode "Errand of Mercy", which established the uneasy treaty of peace between the United Federation of Planets and the Klingon Empire.

Brocco displayed a comedic talent portraying Peter The Waiter for 8 episodes of The George Burns and Gracie Allen Show on CBS during its 1955–1956 season.

[7] Brocco played Colonel Matterson, a patient who used a wheelchair and had dementia, in the Academy Award-winning One Flew Over the Cuckoo's Nest (1975).

He had his ceramics studio in the ground floor, a source of income when he was blacklisted for a while during the red scare of the early 1950s.