The relationship between physical growth and change in mental development on the Griffiths mental development scales was investigated in 127 stunted Jamaican children over a 2-year period. The role of nutritional supplementation in this relationship was examined. There were no consistent associations between changes in weight-for-height or head circumference and developmental change. Height gain over 2 years was significantly associated with change in mental age, and locomotor and hearing and speech subscale scores. Height gain in the first year predicted change in mental age, and hearing and speech in the second year. Some of the effect of supplementation on development was shared with linear growth. Therefore, nutrition probably explains part of the relationship between growth and development. However, supplementation also had effects on development independent of growth. The benefits of supplementation on development and the extent to which they were shared with growth varied among the subscales.