This cross-sectional epidemiological study aimed to identify factors associated with regular cigarette smoking among adolescents. The sample included 517 public school 9th graders in Londrina, Paraná State, Brazil. A structured questionnaire was used to collect information, including social and demographic characteristics, social relations, and health risk behaviors. Logistic regression was used in the statistical analysis, with significance set at 5%. 8.9% of the adolescents reported smoking at least one cigarette a day in the previous 30 days. Age ≥ 15 years (OR = 2.28; 95%CI: 1.21-4.32; p = 0.011) and having friends that smoked (OR = 12.62; 95%CI: 4.44-35.89; p < 0.0001) were associated with regular smoking in both the univariate and multivariate analyses. Meanwhile, gender, race, social class, living with father and mother, religion, maternal education, having tried alcohol, physical activity, and paid work were not associated with smoking. These findings support the development of community-based tobacco control strategies targeting adolescents.