Objective: This study aimed to evaluate the Turkish validity and reliability of the Eastern Ontario Children's Hospital Pain Scale. Method: This methodological study was carried out with 60 children who were between the ages of 1-5 and who had undergone a surgical procedure in the Zonguldak Obstetrics, Gynecology, and Children's Hospital between April and June 2016. For the construct validity factor analyses, translation-back translation for the validity of the language and the Davis technique for the content validity were used. For the reliability, inter-observer compliance, parallel form reliability, item-total correlation, and Cronbach's alpha coefficient were used. Results: There was compatibility among experts' opinions regarding items inclusion on the scale. For reliability, high correlation rates were obtained from independent observers (researcher-nurse) and forms (Eastern Ontario Children's Hospital Pain Scale-Wong Baker Scale) (98.6%, 94.8%) (94.4%, 94.1%). The results of factor analysis were acceptable: the item-total correlation coefficients were between 0.70 and 0.90 and the Cronbach's alpha value was 0.912. Conclusion: The Eastern Ontario Children's Hospital Pain Scale, which was developed by Patrick J. McGrath et al. in the English language, was found to be a valid and reliable scale in Turkish. It is recommended that the scale be used by Turkish health team members in the evaluation of postoperative pain in children.