Objective: to describe the steps in the cross-cultural adaptation process of the Adolescent Pediatric Pain Tool, a pain assessment measure, for use with Brazilian children and adolescents with cancer. Method: a methodological and cross-sectional study was undertaken. The steps in the cross-cultural adaptation process of the tool that resulted in the semantic validation followed an adapted method, including: initial translation, consensus version of translations, evaluation by Expert Committee, back-translation, comparison with original tool and actual semantic validation. Results: the initial translation process of the tool until the final consensus was reached took approximately four months. In the evaluation by the Expert Committee, three health professionals participated in the study, who were knowledgeable on the theme and mastered the English language. In the semantic validation, 35 children and adolescents aged between eight and 18 unfinished years participated, who were patients at the institution where children and adolescents with cancer were treated and monitored. After concluding all steps, the researchers met to discuss the proposed changes. At the end of the cross-cultural adaptation process of the Adolescent Pediatric Pain Tool, all initially proposed 67 pain descriptors were maintained in their Portuguese version. Conclusion: the steps in the cross-cultural adaptation process of the Adolescent Pediatric Pain Tool were executed and described in detail, evidencing the rigorous development of the study.