Differences in temperament between 15 mildly developmentally delayed and 25 normal infants, ranging in age from 3 to 16 months, were examined using the Perception of Baby Temperament Instrument. Delayed infants differed significantly from normals with respect to the temperament dimensions of mood and approach. Mothers described their delayed infants as having lower positive mood scores and as being less approaching, more withdrawing, than did mothers of normal infants. The developmental implications of these findings as well as their impact on models of early intervention are discussed.