<p>The aim this study was to test the psychometric properties and longitudinal measurement invariance of the Subjective Happiness Scale (SHS) in adolescents. This study was carried out in two phases. The first phase comprised a cross-section study with a random sample of 1,134 12-years-old adolescents from Santa Maria, a southern city in Brazil, in 2012. The Brazilian version of the SHS is composed by four items, and was administered by a face-to-face interview. Demographic, socioeconomic and subjective variables were collected by structured questionnaires. Clinical exams were performed by calibrated dentists. Reliability (Cronbach’s alpha - α), discriminant validity and confirmatory factor analysis (CFA) were performed in this phase. Soon after, 771 adolescents were reassessed in 2014. The SHS was administered again. CFA, reproducibility (intra-class correlation coefficient -ICC), convergent validity and longitudinal measurement invariance (MI) were performed. The reliability and reproducibility results were moderate (α=0.51 and ICC=0.70). The scale was able to discriminate subjective happiness between different oral health groups, and socioeconomic status. Convergent validity was satisfactory, demonstrating that the SHS is similar in theoretical concepts with a subjective scale. The CFA revealed a good fit model, confirming the validity of the scale. Moreover, MI showed a goodness-of-fit statistics across time points. The Brazilian version of Subjective Happiness Scale showed adequate psychometric being validy and reliable to be used among Brazilian adolescents.</p>