The first one happened just before five o'clock at the Comfort Inn on East Roosevelt Road. The second happened just after 5:15 at the Shell Superstop, 7400 Cantrell Road.
Police describe the suspect as a black man, 25 to 35, 5'8" to 5'9" tall and weighing about 170 pounds.
The man was armed with a handgun in both holdups, police say.
In the motel robbery, the man ordered a worker to open the cash drawer of a front kiosk, took the money, and ran from the scene before driving away in a vehicle described only as having rounded tail lights.
In the gas station incident, the man walked in and asked for a cigarillo before walking behind the register, pulling out a handgun, and demanding money out of the register. Police say he was last seen running east away from the store towards an apartment across the street and getting into an unknown make and model SUV driven by someone else.