Background: According to the instructions of Iranian traditional medicine (ITM), modification of breast milk through nursing mothers, is the first step in the treatment of infant disorders. In fact, maternal lifestyle, especially diet and eating habits, can change the quality and quantity of breast milk. The modern medical literature emphasizes that exclusive breastfeeding is the optimal nutrition for infants with gastroesophageal reflux disease (GERD). Objectives: The present study was conducted to evaluate the effect of maternal eating principles and diet based on ITM on infantile GERD symptoms. Methods: Exclusive-breastfeeding, under 5 - month infants with clinical diagnosis of GERD and their nursing mothers, were selected for this 6-weeks parallel randomized, controlled trial. All participants were randomly assigned to the intervention and the control group. The mothers of infants in the intervention group received ITM-based dietary principles, and feeding-positioning modifications were trained to the mothers of all infants of both groups, because of observation of ethical issues (not deprived of standard treatment). Age-Specific Questionnaire for Infants (GSQ-I) was used to assess the frequency and intensity of the GERD symptoms. Measuring the difference between the mean Composite Symptom Score (CSS) in week 0, 4, and 6, between the intervention group and the control group, was the main outcome of this study. Results: Both the intervention and control groups had statistically significant differences in the mean CSS of week 4 and 6 compared with baseline (P < 0.05). Also, there was a significant reduction of the mean CSS values in the intervention group compared to the control group (P < 0.05). Conclusions: Maternal eating principles and diet based on Iranian Traditional Medicine appears to affect the reduction of infantile GERD.