Alberto P. León (1909-2001) was the Secretary of Health of Mexico beginning in 1939. He is the 1991 holder of the Mexican National Prize on Medicine and Health. León was born in Irapuato, Mexico, on July 12, 1909 and died on August 4th 2001 in Mexico City. He gained his BS degree at the Preparatory School of Aguascalientes in 1926; his MD at the National University of Mexico in 1933; and MPH degree at the Harvard School of Public Health, USA in 1936. At Harvard he studied under Hans Zinsser. He was Professor of Bacteriology and Immunology at the School of Medicine, National University of México from 1946 to 1950 and since 1946 Professor of Clinics for Infections Diseases.