© GATA.Aim: Determination of the prevalence of risky health behaviors (RHB) of adolescents and evaluation of knowledge of family, school and family physician about RHB. Methods: The study was performed in high schools situated in a district in Ankara. Sample of this research included 1,467 adolescents. Data was collected using a standardized questionnaire under observation from adolescents. Face to face interviews were conducted with mothers, teachers and family health practitioners of some adolescents. Frequencies, ANOVA and independent t test; linear regression analysis were used when appropriate. Ethical consent was taken from Hacettepe University. Results: Mean age of adolescents was 17.15±0.45. In the study, 567 of them had risky health behaviors. The mean score of RHB scale score (t:-0.992, p: 0.321) and the mean scores of subgroups of physical activity (t: 2.261, p: 0.024), nutrition (t:0.48, p: 0.962), hygiene (t:-0.418, p: 0.676), psychosocial t:-2.772, p:0.006) and substance abuse (t:-1.273, p:0.203) of governmental high school adolescents were statistically higher than Anatolian high school adolescents (p<0.05). Families, teachers and family physicians were unaware of RHBs of adolescents (p<0.001; p=0.002; p=0.001). Conclusions: Consequently, this study was important for health professionals worked in primary health services and school health services. The study is evidence that shows school type effects health behaviors of adolescent. On the other hand, it’s seen that family is the most important side of behavioral development. Moreover, adolescents had communication problems with their social environments.