Police were called to the Shell station, 10 North Beacon Boulevard, at 11:58 p.m.
The female employee was attempting to get into her vehicle when an unknown person grabbed her from behind, said Lt. Renee Freeman of the Grand Haven Department of Public Safety.
A struggle ensued and the victim was able to hold onto her purse until the strap broke, Freeman said. The suspect fled the scene east on Washington Avenue with the purse and its contents.
The victim was not injured and no weapon was seen or implied, Freeman said.
Holland Police assisted by searching the area with their K9 unit. Spring Lake/Ferrysburg Police also assisted.
Anyone with information about this incident is asked to call the Grand Haven Department of Public Safety at 842-3460, or Silent Observer at 1-877-88-SILENT (745368).