Background: Healthy lifestyle is an important element for success, especially for Medical students. It includes lots of items such as physical activity, diet, and sleep which we believe that these three items are the major for a healthy lifestyle. The aim of this study is to evaluate healthy and non-healthy behaviors including physical activity, diet and time devoted to sleep, leisure, stress, and smoking of medical students in Qassim region. Methodology: A cross-sectional study was targeted medical students at Qassim region in different cities (Buraydah and Unizah). A self-administered questionnaire was used. It included a domain for physical activity, time devoted for sleep, leisure, and smoking. Results: Around 714 medical students participated in this study, 467 (55.3%) males and 247 (44.7%) females. Regarding physical activity, it was found that one-third of the students excise 1-3 times per week. Regarding diet, 31% of students were always eating there breakfast. But, 81.8% were consuming fast food 1 to 6 times weekly. Furthermore, half of the students devoted 4-6 hours only for sleep during school days and during the weekend they sleep 7-9 hours. Time spent on a cell phone, computer, and surfing Internet (for leisure) was more than 4 hours for 32.5% during the week and it increases at the weekend to 51.9%. Conclusions: Lifestyle of the majority of the students were:  did not sleep enough, did not exercise, consumed fast food, and spent much time in usage of a cellphone, which are common habits among medical students of both genders. These habitats had a significant impact on their overall satisfaction of life and may affect their academic performance and general health.