Police Lt. Bruce Fox tells City News Service the workers were cleaning out the Verdugo Wash in Glendale about five miles north of downtown Los Angeles in anticipation of overnight rain when they found the suitcase Monday morning.
They opened the suitcase, found the body, and called police.
Police Sgt. Tom Lorenz tells KABC-TV that the suitcase was large enough to hold the body, and the man had not been dismembered.
Police say the man was probably killed somewhere else and the body dumped in the wash later.
The coroner's office will determine the man's identity and the cause and timing of his death.