Objective: To investigate attitudes and practices toward smoking among university students and to identify associated factors. Methods: A cross-sectional study was conducted among 1,299 students from five public universities in Thailand. Factor analysis and multiple regression were used for analysis. Results: A higher score of anti-smoking attitude was associated with female gender, majoring in science, living on campus, having a father with primary or secondary school, and those whose father was employed in the private sector. A more positive perceptions about smoking was associated with male gender, having a family income of 30,001-50,000 baht, and having a smoking friend. High positive preventive practice score was associated with those who came from rural areas, having a mother who was self-employed, and having a smoking family member. Conclusions: Although students showed strong anti-smoking attitudes, their preventive practices were poor. These findings should be taken into consideration when developing preventive smoking programs.