The sensorimotor developmental phase, leading to a gradual acquisition of skilled actions, is of crucial importance for the young child and its growing sense of competence. Three vital steps in motor development are mentioned: first, the smooth and spontaneous movements of the "graceful and elegant" baby, expression of his well-being and vitality, with their profound effect on the mother-infant relationship; second, the emergence of intentional and goal-oriented acts leading to Funktionslust and playful repetitions; and finally, the development of symbolic acts and increasing technical capacity to use playthings in imaginative play. The psychodynamic significance of the most important motor milestones for the child's ego development is set out. Motility is one of the most important avenues for exercising such functions as mastery, integration, reality testing (self-preservation), and control of impulses. One may consider this early childhood period of rapid motor development as the motor phase of ego and libido development. Hence, many forms of developmental psychopathology are attended with motor impairment or insufficient motor mastery and integration. From that clinical perspective pass in review: perinatal complications and motor disturbance, attention deficit/hyperactivity disorder, dissociated motor development, low birth weight children and their developmental difficulties, developmental coordination disorder, aspects of pervasive developmental disorder, and stereotypic movement disorder.