Investigators said the takeover-style robberies all happened in just about an hour.
The men were wearing masks, police said, when they robbed the Denny's near T.C. Jester and Highway 610.
They were reportedly armed with a long gun and a pistol.
Police said they robbed the business and customers before fleeing the scene in what is described as a small white 4-door vehicle. Witnesses told police it was possibly an Oldsmobile or a Buick.
Minutes later, police got calls at two other restaurants. One was an IHOP at Highway 290 and Hollister, the other was a Denny's at 290 and Pinemont.
Right now, police are reviewing surveillance video and interviewing witnesses to try and get more information about the suspects.
No one was hurt during the robberies. It's unclear how much money the robbers got away with.
Anyone who might know anything about the robberies is urged to call Houston police.
Report a typo to the ABC13 staff