Police say Dakota Taylor, 22, and his younger brother Jeffery Taylor, 20, shot a store clerk at Porky's Truckers' Store on Highway 301 North at South of the Border in Dillon County last August.
Court officials say the brothers pleaded guilty this week.
A judge sentenced the younger Taylor to 12 years and his older brother to 18 years in prison for attempted murder, armed robbery and possession of a weapon during the commission of a violent crime.
The men will serve at least 85% of their sentences before their eligible for parole.