Background and Objective: Ignoring pain especially in infancy causes serious complications. Considering recent studies about sedative effect of breast-feeding and oral glucose on neonates, this study was performed to survey each method after neonatal period.

 Materials and Methods: This study is a triple blind clinical trial on 211 infants aged 2, 4,and 6 months, which were randomly categorized into control, breast-fed, and oral glucose groups. Interventions were performed two minutes before injecting DPT vaccine.  The infants’ reactions were recorded before, during, and after intervention. Two experts evaluated pain intensity by Modified Behavioral Pain Scale (MBPS). The crying duration was measure by chronometer in second. 

 Results:  Pain intensities for breast-fed, oral glucose, and control groups were 5.77±0.18, 6.63±0.16, and 5.87±0.22, respectively. Least Significant Difference (LSD) test showed that MBPS was significantly lower in breast-fed compared to oral glucose group (P value=0.014). The difference between breast-fed and control groups was not significant. Crying duration did not have significant difference among the three groups.

Conclusion: It seems that breast-feeding has better effect on vaccination pain compared to oral glucose.