Police received reports at 9.04 am of “a possible unexploded device” in Market Street, Abbotsbury.
The coast road was closed in both directions for nearly 6 hours, between the junctions of Abbotsbury Hill and Rodden Row.
A 100-metre cordon was put in place.
The Coast road re-opened shortly before 2.30 pm.
Heavy traffic was reported prior to the road re-opening
Dorset Police said: “The B3157 West Street in Abbotsbury has reopened following a report of a possible unexploded device.
“The EOD has attended and removed the item. We want to thank the public for their patience and understanding while the road closure was in place.”