Objectives: To investigate the prevalence of and attitudes to smoking among third year medical, pharmacy, dentistry and nursing students in Lao People's Democratic Republic (PDR). Design: A cross-sectional survey conducted among third year university level, health professional students. The survey used a self-administered questionnaire which was originally developed by WHO, and modified to suit the setting. Setting: The setting was the University of Health Sciences in Vientiane, the capital of Lao PDR. Participants were recruited from the Faculties of Medicine, Pharmacy, Dentistry and Nursing. At the time of the survey, 521 third year students were enrolled. Primary and secondary outcome measures: The primary outcome measure was prevalence of current cigarette smoking and other tobacco use. Smoking status was categorised as: current smoker, ex-smoker and non-smoker with current smokers defined as those who had smoked cigarettes or used other tobacco on one or more days during the previous 30 days. Results: In total, 506 respondents completed the questionnaire, giving a response rate of 97.1% to 98.5% across the different faculties. Overall smoking prevalence was 5.07% (95% CI 3.2% to 7.1%), which is lower than previously reported national prevalence rates. Women reported smoking less than men did (OR=0.56, 95% CI=0.013 to 0.242; p=0.003). The majority of students supported tobacco control measures. The number of people who reported receiving formal training in tobacco cessation counselling ranged from 10.9% (95% CI 5.3% to 19.1%) among nursing students to 51.1% (95% CI 40.4% to 61.7%) among medical students. Conclusions: Smoking prevalence among this cohort was relatively low. Students were supportive of tobacco control policies. Further research is needed to understand what is working in this context, in order to apply lessons learnt in similar settings. In the meantime, health professional students should be provided health education to discourage tobacco use. Information on tobacco control policies needs to be more widely disseminated.