Background: The aim of this study was to evaluate the efficacy of the topical use of chamomile oil as a complementary method in the improvement of infantile colic symptoms. Methods: This randomized controlled trial was carried out on 74 infants with colic at Sabzevar University of Medical Sciences in Sabzevar, Iran. The infants were randomly allocated into two groups. In the intervention group, chamomile oil was applied topically on the abdominal region three times a day for 14 days. The placebo group received paraffin oil in a similar manner. A data collection form was daily filled out for all infants by their parents. Number and duration of crying episodes and duration of sleep were assessed at the baseline and on the 7th and 14th days of the intervention. Results: Results showed that there was a significant difference in the crying time of the two groups on days 7 and 14 as compared to that at the baseline (P=0.03 and P=0.002, respectively). There was a significant increase in sleep duration only on the 14th day of treatment as compared with that at the baseline (P=0.01). Although the number of crying episodes in both groups decreased, there was no significant difference between the two groups (P=0.08). Based on the regression test, although the values obtained on days 1 and 7 were not statistically significant, compared to those at the baseline, the number of crying episodes decreased on the 14th day (95% CI: -115.39 to -15.04; P=0.012). Conclusion: Topical consumption of chamomile oil may be used as a complementary, safe, and cost-effective way to improve and reduce the symptoms of infantile colic.