The Chilean physician Abraham B Horwitz (1910-2000) was an outstanding personality of World and Pan American public health during the second half of the twentieth century. He was member of a family that, emigrating due to ethnic persecutions in Russia, took refuge in Chile. He became a relevant physician, a specialist in infectious diseases and public health. He was highly influential in the birth of the Public Health School at the University of Chile and the Chilean Health Service. He became Executive Director of the Pan American Health Organization, holding that position for 16 years. During this period, the institution experienced a great development. He stimulated research in the areas of basic sanitation, nutrition and eradication of transmissible diseases. He also opened unexplored areas such as the relation between economy, modern administration and health. During his last years, he chaired a successful Nutrition Committee at the United Nations. The most outstanding achievement of this Committee was the promotion of widespread vitamin A use. His intellectual and social deed is continued by The Pan American Foundation for Health and Education and this institution established an annual prize in his memory. (Rev Méd Chile 2003; 131: 929-34)