Authorities hanged Alireza Mafiha, 20, and Mohamad Ali Sorouri, 23, Sunday from a crane before a crowd of 100 onlookers, the Los Angeles Times reported.
Police arrested the men in December after footage, taken from a security camera, was posted online, the Los Angeles Times reported.
The video apparently shows the men ride up to the victim on two motorcycles driven by two other men. They can be seen threatening the man with a dagger and taking his cash, bag and coat.
Mafiha and Sorouri were convicted of moharebeh, or waging war against God, a capital offense, the Times reported.
Some observers of the hanging said they thought the punishment was too harsh for the crime.
"Nobody was killed so they should not be hanged," an elderly man said.
"Hanging them is too harsh," another onlooker said. "It is better to cut off their hands."
Others thought the punishment fit the crime.
"Mugging has now become a profession for some people," one observer said.