The water pumps are allowing air bubbles to enter the cooling systems, which slows water circulation and reduces performance, Mibz reported Tuesday.
The problem, which has not caused any accidents or personal harm, could result in reduced power.
Triangle Biz Journal said 378,000 U.S. Prius were affected by the recall.
Globally, about 650,000 Prius vehicles were involved, Mibz reported.
Toyota said it would contact Prius owners and begin repairs in December.
On recalls, Toyota has had a tough year. The company has recalled about 14 million vehicles in 2010, many of them involving a potentially dangerous problem with unexpected acceleration.
Copyright 2010 United Press International, Inc. (UPI).