Infantile colic (IC) is a distressing condition with an unclear etiology. A prospective trial was undertaken to study the hypothesis that medication during labor increases the risk of IC. Of 365 singleton deliveries, 70 (19%) developed IC. The factors associated with a significantly increased occurrence of IC were: a "psychological" complication of pregnancy, a sibling with a history of IC, a bad subjective experience of pregnancy and second parity. No significant association to "true" obstetrical complications or labor occurrences (breech, vacuum extractor, cesarean section, shoulder dystocia, pudendal block, epidural analgesia, general anesthesia or intravenous Syntocinon) was found. Modern management of labor does not increase the risk of IC. Prevention of IC is therefore achieved by psychological support to the pregnant women in the risk groups, and not by depriving her of necessary obstetrical management or pain relief.