Officers found a total of 19 gambling video games in the café, although none of the 21 detainees were armed.
Community members had been complaining to police officials about activity happening within the building at all hours of the day.
Since the complaints, the police had been investigating the café for the best part of a year.
Anthony Bertagna, a spokesman for the Santa Ana Police Department, said they had accumulated enough evidence from the investigation to obtain a warrant to search the building, prior to raiding it on Wednesday.
It remains unclear who the owner is, as the investigation continues.
