The robberies happened between 1:30 a.m. and 5 a.m. and police are still looking for clues.
They said this is a very unique case and believe the same person may responsible for all three robberies.
The first robbery took place at a 7-Eleven store in the 1000 block of South 38th Street; the second one was reported at another 7-Eleven in the 3100 block of 6th Avenue; the third at a Safeway on the 2400 block of Proctor St.
Police said the victims in all three locations described the robber as a black man in his 20s to 30s.
They believe the robber drove around and looked for businesses with only a few customers and employees working before he struck.
"The suspect description is very similar in each of the robberies and the clothing description was the same a black hoodie and black pants," Loretta Cool of the Tacoma Police said.
At each of the robberies the suspect walked into the business took a look around waited a few minutes and pulled a gun and demanded cash from the clerk.
Surveillance video shows the robber from the first incident coming up to the counter and approaching the clerk like a typical paying customer. He pulls out a semi-automatic handgun, as she opens register, and looks down and turns away from the suspect and steps aside from the register.
He grabbed the entire cash drawer, went through it and took off in a matter of moments.
Police are working to find evidence to connect the incidents and say they're glad no one was hurt.
Anyone with information is asked to contact authorities in Tacoma.