This study investigates the relationship between having an older sibling and early goal-directed motor development. In a longitudinal study, infants were filmed playing with their mother and were observed at 5 and 12 months of age. After each observation, they were assessed with the Mental Bayley Scale. From the mother-child interaction, playing was coded in terms of the production of infant goal-directed actions. Results indicated that infants with siblings produced fewer goal-directed actions at 5 months than infants without older siblings, but at 12 months they produced relatively more goal-directed actions than infants without older siblings. There was no relationship with scores on the Mental Bayley Scale. In order to examine differences in adult behavior that may account for variation in infant motor performance, maternal level of motionese was scored with no differences found between the sibling-no sibling groups. (Contains 1 figure.)