The devices were found on Friday morning at the Hess Station at 506 North DuPont Highway by inspectors from the Weights and Measures Section of the Delaware Department of Agriculture.
They notified state police who arrived to remove the devices.
Skimming devices are designed to steal information from credit cards used at the pumps. Police say they do not yet know if any information was successfully stolen.
Anyone with information is asked to contact the Troop 2 Financial Crimes Unit at 302-834-2630 extension 212.