All the male students in a high school in Brescia, North Italy (about 195,000 inhabitants) in Grades 9 through 13 were given a self-administered anonymous questionnaire during school time. Among the 1,462 students who filled in a valid questionnaire, 29.1% claimed to practice one or more sports regularly (at least 4 hours/week for 9 months/year or more), 30.2% practice sports occasionally, and 40.7% no sports at all. The percentage of current smokers (at least one cigarette a month) increased from 9th grade (11.1%) to 10th (13.2%), 11th (15.2%), 12th (27.7%), and 13th (23.7%) grade. The percentage of smokers showed a steady linear increase from the lowest to the highest grade in students practicing no or occasional activity but no increase in those who regularly practice sports. Students' smoking was negatively associated with the regular practice of sports among 12th-13th grade students.