Research over the past three decades has shown that early intervention in infants biologically at risk of developmental disorders, irrespective of the presence of a brain lesion, is associated with improved cognitive development in early childhood without affecting motor development. However, at present it is unknown whether early intervention is also able to improve developmental outcome in infants with a serious lesion of the brain. This paper discusses factors that might play a role in the effect of early intervention. The following picture emerged from the limited evidence available: (1) coaching of parents seems an effective means of intervention; (2) our understanding of the plasticity of the developing human brain is currently too limited to allow a direct practical implementation in early intervention; (3) intervention before term age should primarily focus on stress reduction, intervention after term age on stimulation of infant development; and (4) our knowledge of the best ways to stimulate infant development is scant. Nevertheless, preliminary data suggest that offering the infant ample opportunities to explore by self-produced motor activities the borders of their own abilities might be a good strategy for promoting developmental outcome, including functional mobility.