AIM: To assess the incidence of infantile colic and its association with variable predictors in infants born in a community maternity hospital, Tehran, Iran. METHODS: In this prospective cohort study, mothers who gave birth to live newborns between February 21 and March 20, 2003 at the hospital were invited to join to the study. For every infant-mother dyad data were collected on infant gender, type of delivery, gestational age at birth, birth weight, birth order, and mother’s reproductive history. Then mothers were given a diary to document the duration of crying/fussiness behav-iors of their infants for the next 12 wk. We scheduled home visits at the time the infants were 3 mo of age to collect the completed diaries and obtain additional information on infants’ nutritional sources and identify if medications were used for colic relief. Cases of colic were identifi ed by applying Wessel criteria to recorded data. Chi-square and Mann-whitney U tests were used to compare proportions for non-parametric and para-metric variables, respectively. RESULTS: From 413 infants, follow-up was completed for 321 infants. In total, 65 infants (20.24%) satisfi ed the Wessel criteria for infantile colic. No statistical sig-nifi cance was found between colicky and non-colicky infants according to gender, gestational age at birth, birth weight, type of delivery, and, infant’s feeding pattern. However, fi rstborn infants had higher rate for developing colic (P = 0.03). CONCLUSION: Colic incidence was 20% in this popu-lation of Iranian infants. Except for birth order status, no other variable was signifi cantly associated with in-fantile colic. AIM: To assess the incidence of infantile colic and its association with variable predictors in infants born in a community maternity hospital, Tehran, Iran. METHODS: In this prospective cohort study, mothers who gave birth to live newborns between February 21 and March 20, 2003 at the hospital were invited to join to the study. For every infant-mother dyad data were collected on infant gender, type of delivery, gestational age at birth, birth weight, birth order, and mother’s reproductive history. Then mothers were given a diary to document the duration of crying / fussiness behav-iors of their infants for the next 12 wk. We scheduled home visits at the time the infants were 3 mo of age to collect the completed diaries and obtain additional information on infants’ nutritional sources and identify if medications were used for colic relief. Cases of colic were identifi ed by applying Wessel criteria to recorded data. Chi-square and Mann-whitney U tests were used to compare proportions for non-parametric and para-metric variables, respectively. RESULTS: From 413 infants, follow-up was completed for 321 infants. In total, 65 infants (20.24%) satisfi ed the Wessel criteria for infantile colic. was found between colicky and non-colicky infants according to gender, gestational age at birth, birth weight, type of delivery, and, infant’s feeding pattern. However, fi rstborn infants had higher rate for developing colic (P = 0.03). CONCLUSION: Colic incidence was 20% in this popu-lation of Iranian infants. Except for birth order status, no other variable was signifiantly associated with in-fantile colic.