Disorders of the motor system in children may present acutely or insidiously. The underlying pathologic process may involve the central nervous system or the peripheral nervous system. Some causes of weakness or clumsiness are treatable; others have important prognostic implications for the child. The primary care physician should understand how to take a thorough history and localize the process with the physical and neurologic examination, to decide on further evaluation and management of the child with motor dysfunction.