OBJECTIVE: The aim of this randomized, double-blind, placebo-controlled trial was to investigate the effectiveness and side effects of a phytotherapeutic agent with Matricariae recutita, Foeniculum vulgare and Melissa officinalis in the treatment of infantile colic. METHODS: 93 breastfed colicky infants were enrolled, the diagnosis was made according to Wessel's criteria. After a 3 day observation period, the infants were randomly divided into two groups, one treated with phytotherapeutic agent (PA) and the other with placebo twice a day for 1 week. Crying time and side effects were recorded. RESULTS: 88 infants completed the trial: 41 in the PA group and 47 in the control. The daily average crying time for the PA was 201.2 min/day (SD 18.3) at the baseline and 76.9 min/day (SD 23.5) at the end of the study; for the placebo it was 198.7 min/day (SD 16.9) and 169.9 min/day (SD 23.1) (p < 0.005). Crying time reduction was observed in 85.4% subjects for the PA and in 48.9% subjects for the placebo (p < 0.005). No side effects were reported. CONCLUSION: The present study shows that colic in breastfed infant improves within 1 week of treatment with an extract based on Matricariae recutita, Foeniculum vulgare and Melissa officinalis. (c) 2005 John Wiley & Sons, Ltd.