Understanding why adolescents smoke is essential for developing efficient smoking prevention programmes among teenagers. Hence, the objective of our study was to assess the factors associated with smoking among Romanian adolescents. A cross sectional written survey was conducted among 473 students aged 15-17 years from 5 senior high schools in Cluj-Napoca, Romania (May/June 2004). All students filled in an quesstionnaire which assesed their smokingrelated behaviour.One quarter (24.5%) of the subjects were smokers. Adolescent’s attitudes regarding smoking and the smoking behaviour of the best friend were important factors related to smoking behaviour. Adolescent smoking was also strongly associated with low self–efficacy expectations to refuse smoking in different situations and with intention to smoke in the next year. The results suggest the need for strengthening positive attitudes towards non-smoking, resistance against peer influences and for enhancing self-efficacy beliefs to refuse smoking in order to prevent smoking among Romanian adolescents.