The aims of study were1) to present a unified Portuguese-language version of the Perceived Health Competence Scale (PHCS) and to evaluate their psychometric properties in unifactorial and bifactorial models, and 2) to estimate the influence of demographic variables and body mass index (BMI) on perceived health competence in Brazilian, Portuguese and Mozambican students. Face and content validity of PHCS were performed. The convergent, discriminant, concurrent validity and the reliability were assessed. The invariance was estimated using multi-group analysis. In structural models, the PHCS’ factors were used as dependent variable and demographic variables and BMI as independent variables. The probability for low expectations about outcomes and perceived competence in health-related behaviors was estimated by logistic multiple models. Overall 3,248 students participated in this study. The unified version was well understood in the three countries. PHCS’ bifactorial model showed good fit. In Mozambican sample the convergent validity and reliability were limited. The invariance was showed only in the independent samples. Higher expectations about achieving desired health outcomes were associated to study-related medication use, BMI≥25.0 kg/m2 , low socio-economic stratum and older age. Greater health competence in health-related behaviors was associated with no medication use, BMI<25.0 kg/m2 , high socioeconomic stratum, younger age and male gender
