To examine the pain relieving effect of breast feeding during DPT immunization injections in healthy neonates.

76 healthy 2– 4 months years old term infants, which had been brought to the health centers of Tehran University of Medical Sciences in West of Tehran for DPT vaccination by their mothers was involved in this randomized controlled trial study. (Their parents signed informed consent, Year 2008–2009) By randomized collection one group were breast-fed, 2 minutes before, during, and 15 seconds after the DPT immunization injection, and second group according to routine of clinic lied on the examining table during DPT Vaccination. Objective changes in appearance of Neonates were assessed by Modified Behavioral Pain Scale (MBPS) during 5 second before immunization till 15 second after it.

The equality between two groups according to age, gender and the time of feeding prior to vaccination were checked, there weren’t correlation. There were significant differences in Behavioral Pain Scores of two groups in all parts include: facial expression (4 items), cry (5 items), and movements (6 items). (P < 0.0001)

Regarding to significant difference in behavioral of Pain responds in two groups, it is suggested that, with simple and safe intervention of straight breast feeding, health care workers, and physicians reduce pain during immunization and muscular injections too.