The successful physical and occupational rehabilitation of cerebral palsied children is dependent primarily upon the efficient learning of motor skills. A mastery of motor fundamentals (i.e., pre-functional activities) and the acquisition of complex, integrated motor patterns (e.g., eating, dressing, washing, etc.) often represent important therapeutic goals. The development of such motor skills is influenced, to a large extent, by the child's interests and attitudes toward treatment. The importance of motivational variables is reflected, too, in the fact that long and arduous retraining procedures in which the handicapped child participates tend often to produce discouragement and a consequent lack of effort toward attaining treatment goals. Even prior to the inception of therapy, it frequently has been observed that many chronically handicapped children lack the drive and interest which are necessary for learning self-help activities. These observations emphasize the importance of understanding the influence of motivational factors on the motor performance of the cerebral palsied child. The present study sought to determine the effect of success and failure in securing material rewards on the cerebral palsied child's speed of performance of a pre-functional activity similar to those taught in the hospital's occupational therapy department. It was decided to use material rewards because such incentives had been found by other investigators to be successful in improving the verbal and motor behavior of non-handicapped children. Certain fairly consistent findings from these previous studies are as follows: I. The greater effectiveness of reward and reproof in facilitating performance as contrasted with non-incentive conditions (1, 2, 3, 5, 6). 2. The gradual decline in the effectiveness of repetitive, standardized