This study investigates the impact of infantile colic on subsequent development. Infants with a history of colic scored significantly lower on the Mental and Psychomotor scales of the Bayley Scales of Infant Development at age 6 months but there was no significant effect of colic on test performance at later ages. The data suggest that this temporary delay in development may be due in part to less favorable patterns of caregiver-infant interaction as a result of the history of colic.