BACKGROUND: Puberty is a transition period making physiological development a challenge adolescents have to face. Early pubertal development could be associated with higher risks of poor health. Our objective was to examine risk behaviours, physical and psychological determinants associated with early menarche (<11 years). METHODS: Early menarche was assessed in the Health Behaviour in School-aged Children French cross-sectional survey. Data were collected in 2006 by anonymous self-reported standardized questionnaire from a nationally representative sample of 1072 15 years old girls in school classrooms. Family environment, school experience, physical and psychological factors, risk behaviours (substance use and sexual initiation) were recorded. Logistic regression models were applied (analysing for crude and adjusted relationships between early menarche and risk behaviours controlled for family context). RESULTS: Median age at menarche was 13.0 years; 57 girls (5.3%) were early-matured. Controlled for familial environment, early menarche was associated with having had more than two life-drunkenness episodes (adjusted OR = 2.5 [1.3-4.6]), early sexual initiation (adjusted OR = 2.8 [1.3-6.0]) and overweight (adjusted OR = 7.3 [3.6-14.9]). CONCLUSION: Early-maturing girls may affiliate with older adolescents, hence engage in risk behaviours linked to their appearance rather than their maturity level. Factors associated with early menarche highlight the need to focus attention on early-matured girls to prevent further health problems linked to risk behaviours.