Smoking is a well-known preventable cause of cancer. Today, almost 1.3 billion of people are smokers and this number is expected to increase to 1.6 in 2025 globally. In this study, we aimed to determine prevalence and determinants of smoking among first year students at Hacettepe University. In 2004, the total number of the subjects participated in the study were 1050. Of the total participants, 69.0% were female. Mean age of the students was 19.8±1.6 years. “Alcohol consumption”, “being less careful about his/her self health care”, “not having smoke-free policy at the university”, and “not supporting smoke free cafeteria concern at the university” were found to be risk factors of smoking. First year students, in a period where the prevalence of this addiction usually tends to increase, are a particular target group for the implementation of prevention activities. [Turk J Cancer 2006;36(2):49-56].