Background and­ Objective: ­­ Pain is a multidimensional phenomenon defined as­“an unpleasant sensory and emotional experience that is ­ associated with actual or potential tissue ­damage”­.­Infants and children are vaccinated before two years on several occasions. Many of these vaccines are injectable, and are painful. The aim of this study was to evaluate whether topical tetracaine can reduce the pain of IM DPT injection compared to placebo in infants of two months of age.

  Material and Methods: ­ In this study, 40 infants aged two months were selected by convenience sampling and randomly placed in two groups of case and control. The Infants of experimental group were injected by using topical tetracaine gel %4­­ and those of the other group by a placebo. The intensity of injection was scored by a pediatric registered nurse, using the FLACC pain scale.

  Results: Although the mean of pain intensity in case group (8.3) is lower than that of controls (9.1) and also the time of pain relief, the use of tetracaine could not be significantly effective in reducing the severity of pain due to intramuscular injection of DPT vaccine. Conclusion:­ ­ Based on the results, there is no significant difference between case and control groups on using tetracaine, but because of low pain intensity in case group, further researches are needed to be done.

  Key words: Pain, Infants, ­Tetracain gel, Intramuscular injection