We study how patient-regarding altruism is formed by medical education. We elicit and structurally estimate altruistic preferences using experimental data from a large sample of medical students (N = 733) in Germany at different progress stages in their studies. The estimates reveal substantial heterogeneity in altruistic preferences of medical students. Patient-regarding altruism is highest for freshmen, significantly declines for students in the course of medical studies, and tends to increase again for last year students, who assist in clinical practice. Also, patient-regarding altruism is higher for females and positively associated to general altruism. Altruistic medical students have gained prior practical experience in healthcare, have lower income expectations, and are more likely to choose surgery and pediatrics as their preferred specialty.