ABSTRACT Objective: To translate, cross-culturally adapt and validate the Sickle Cell Self-Efficacy Scale for application in the Brazilian cultural context. Methods: This is a methodological study performed in 6 steps: 1- Forward translation; 2- Translation synthesis; 3- Back-translation; 4- Assessment by expert committee, with computation of the Content Validity Index (CVI); 5- Cultural adequacy (pre-test); 6- Reproducibility. A pre-test was performed with the participation of 10 adolescents/young adults with sickle cell disease through a telephone call and their responses were recorded on a form in a web platform. The instrument validation step was carried out with 55 adolescents/young adults with sickle cell disease, 43 of them having participated in the retest. The analysis of internal consistency and reproducibility was calculated using the Cronbach’s alpha coefficient and the Intraclass Correlation Coefficient (ICC), in the R statistical programming environment. Results: The translated instrument had good acceptance among the experts, reaching an average CVI of 1.0. In assessing reliability, the scale showed acceptable internal consistency, with a Cronbach’s alpha of 0.84. In the agreement analysis, the ICC was 0.923 (95% CI: 0.857 to 0.958), which indicates good temporal reproducibility. Conclusions: Following the process of translation, cross-cultural adaptation and validation, we obtained the Brazilian version of the Sickle Cell Self-Efficacy Scale, considered valid and reliable to be applied to adolescents and young adults with sickle cell disease in Brazil.