To understand the way pain is produced and perceived is very important for its relief. In recent years, important advances have been made regarding the evaluation of pain, with the validation of objective criteria such as Oucher pain scales, body diagrams, numerical scales, verbal descriptive scales and visual analogue scales. The objective evaluation of pain is of special importance in pediatrics given the difficulties inherent to the patients of this group. The purpose of this study was to determine how nursing professionals evaluate pain in hospitalized children. We employed a questionnaire to nursing professionals (nurse technicians, practical nurses and registered nurses) that work in the pediatric service of a teaching hospital. Fifty-six professionals (100% women) answered the questionnaire. Of these, 55 (98.2%) stated that they knew the methods and cited vital signals, physical examination and patient behaviors as items for evaluation. Although the majority of professionals (98.2%) have reported knowledge of objective methods (scales) for pain assessment in children, there was a predominance of behavioral observation as a method of choice (prevalence ratio 2.27; 95% confidence interval: 0.9 to 2.38). No significant associations or differences were observed between professional category, time of experience, other variables, and the type of method employed. The selected professionals do not use scales or other objective methods to measure pain in children. Therefore, it is necessary to habilitate and train nursing professionals working with pediatric patients in pain so that they will be able to assess their pain in an adequate manner.