The man, whose name was not released, had crawled into a hole in the trunk leading to a cavity about 4 or 5 feet underground in Laguna Hills, The Orange County (Calif.) Register reported Tuesday.
Battalion Chief Kris Concepcion of the Orange County Fire Authority said only the man's head and arms were visible and it took 90 minutes to retrieve the equipment necessary to cut him free.
Firefighters were called to the scene to check the man's mental health.
"Why he's in a tree, I have no idea," Concepcion said.
It is unknown how long the man was stuck in the tree, and he was freed without suffering any injuries, the Los Angeles Times reported.