The aim of the present study is to provide evidence for the role of action used mainly by children with cerebral palsy to get over difficulties in some mental rotation tasks. 25 children with cerebral palsy and 25 able children were given a task inspired from the Tétris video game consisting in fitting together geometrical figures. Results show that children with cerebral palsy are able to anticipate mentally the motion of the object, but they can not mentally break down the motion. This may be explained by the use of an object manipulation strategy necessary to actualize the properties of the object motions. These findings have implications in the understanding of the role of action in the development of mental imagery.