Becoming a medical professional is a gradual process that begins at entry into medical school and continues throughout the entire training period. Four events mark key stages in this process: entry into medical school, beginning of clinical rotations, graduation and beginning of independent practice. Essential characteristics of student professionalism are commitment, honesty, discretion, cooperation, participation, diligence and temperance. Students need to know how to deal with unprofessional behaviour, whether their own, other students’ or teachers’. Medical schools must have comprehensive programmes for teaching and supporting student professionalism.