Red Deer RCMP responded to a report of a robbery with a weapon at the south Walmart location at about 11 p.m. on Thursday.
Police said an adult female pointed what is believed to be a firearm at an employee after being confronted about items she was attempting to steal.
A confrontation ensued, but no one was injured.
The suspect fled to a waiting vehicle in the parking lot. Police combed the area, but did not find the vehicle.
The incident is still under investigation.