Objectives. Recently, adolescents fall short of adequate physical activity (PA) requirements, though the benefits of active lifestyle are well documented. In this study, we analyzed how the PA is associated with life satisfaction among adolescent girls and boys. Methods.Data for this study were collected in April–June 2018 during the international HBSC survey in Lithuania (n = 4191, aged 13.9 ± 1.69 years). From self-report questionnaire, the indicators reflecting PA, life satisfaction, body image, somatic complaints, wellbeing, demographic, and socioeconomic status were analyzed. Bivariate analysis used Chi-squared test, multivariate associations—logistic regression method. Results.Moderate-to-vigorous PA was sufficient among 18% of schoolchildren, while 66% of respondents met vigorous PA requirements. For boys vigorous PA can be regarded as the predictor of better life satisfaction (OR = 1.63, p < 0.05), while for girls the moderate-to-vigorous PA is observed as a risk factor for lower life satisfaction at borderline significance (OR = 0.67, p = 0.053). Conclusions.Addressing the PA and life satisfaction interplay, we identify essential differences between genders. Schools, parents, and policy makers should enable the adolescents with more opportunities and equipment for vigorous rather than moderate-to-vigorous PA.