Police responded to a burglary alarm at the popcorn shop near North Clark and West Grace streets around 1:30 a.m. Friday.
The cash register was found behind a nearby building. Other items from the register were found a block away.
Two months ago, the store was hit twice in a week.
On Thursday, at least four businesses in the city's Lincoln Park neighborhood were broken into. Burglars smashed the glass and grabbed cash from registers before running off.