This study aimed to translate, adapt linguistically and culturally, and validate the Portuguese version of the Children's Assessment of Participation and Enjoyment/Preferences for Activities of Children (CAPE/PAC). CAPE/PAC is a tool that measures the participation of children and youth with and without disabilities in leisure activities, considering behavioral, contextual and affective aspects. The Portuguese version resulted from a process of translation, back-translation, analysis by experts and pilot application to obtain evidence of content validity. The instrument was administered with 361 children -- 306 without disabilities and 55 with disabilities -- from five school clusters in the district of Porto, aged 6 to 18 years old. Data were analyzed for internal consistency -- to determine the degree of homogeneity of the instrument's items -- as well as for the standardization of the participation of children and youth with and without disabilities, and their comparison with evidence from studies evaluating similar constructs. The results revealed that the Portuguese version of CAPE/PAC exhibits emerging evidence of reliability and validity.