The aim of this study is to evaluate the smoking status of medical students. This descriptive research was conducted in a medical school with 544 students from first to sixth terms in Istanbul. Online survey form was used in the research. Statistical analyzes were done using SPSS 22.0 program. The mean age of the students participating in the study was 21.0±2.2, 55.7% of them were women and 55.1% of them were living with their families/relatives. It was determined that 6.4% of the students were smoking before joining university, 10.7% were regular/frequent smokers, the average number of cigarettes smoked daily was 10.2±7.5, and the reason for starting smoking was stress in 39.9 percent. It was determined that 62.9% of the smoking students thought to quit smoking and 66.1% knew the methods of quitting smoking. The frequency of regular/frequent smoking was found to be higher in those living alone or with friends at home, and those whose mothers and siblings smoked regularly/frequently. In our study, it was determined that more than half of regular/frequent smokers started smoking before university and the most common reasons for starting were stress, friend influence, and curiosity. It is recommended that awareness trainings about smoking harms be included in different grades in the National Education curriculum and that students should be trained in stress management and choosing friends.