This study aimed to evaluate the factors associated with psychological well-being among adolescents in a southern Brazilian city. A cross-sectional study was performed with a representative sample (n = 960) of adolescents (15-18 years). Eighty-six households were visited in each of the 90 randomized census tracts. Parents signed a written consent form before the adolescent answered a self-reported questionnaire. Psychological well-being was evaluated with a scale containing seven figures representing expressions varying from extreme happiness to extreme sadness. Adolescents were asked to mark the figure that best resembled the way they felt about their lives, and 72.33% reported a high level of psychological well-being. Prevalence of psychological well-being was higher in families with better economic status and higher maternal schooling. Adolescents who practiced a religion, did not smoke or consume alcohol, and wished to lose weight showed a higher level of psychological well-being, suggesting an interrelationship between health behaviors.