Objectives: The aim of this study was to evaluate the efficacy on crying episodes owing to infantile colic of a new infant formula containing partially hydrolysed whey proteins, prebiotic oligosaccharides (OS), with a high b-palmitic acid content. Design: Prospective randomized controlled study. Setting: Italy. Subjects: Two hundred and sixty-seven formula-fed infants, aged less than 4 months, with infantile colic, were randomized to receive either the new infant formula (study treatment (ST)) or a standard formula and simethicone (6 mg/kg twice a day) (control treatment (CT)). A questionnaire was given to parents to evaluate for 14 days the daily number of colic episodes and crying time. Results: Out of the 199 infants who completed the study, 96 were treated with the new formula and 103 were not treated. Infants receiving the new formula had a significant decrease in colic episodes after 1 week (2.4771.94 at day 7 vs 5.9971.84 at the study entry) compared to infants receiving the CT (3.7271.98 at day 7 vs 5.4171.88 at the study entry) (Po0.0001). Also at day 14, the crying episodes were significantly different between the two groups of infants (1.7671.60 in ST vs 3.3272.06 in CT) (Po0.0001). Conclusions: The use of a partially hydrolysed formula supplemented with fructo-and galacto-OS induces a reduction of crying episodes in infants with colic after 7 and 14 days when compared with a standard formula and simethicone.