Since their inception in 1901 the Nobel Prizes in Medicine and Physiology(M&P) have been awarded 88 times for some of the greatest discoveries in medical history. In this study we assessed the impact of these awards on some aspects of 20th century medicine with emphasis on pediatrics.Methods: We analyzed some biographic data and various characteristics of the prizes using standard publication sources, and materials from the Nobel Foundation. For a temporal perspective, we contrasted the findings from 1901-44 (Period A) with those from 1945-97(Period B); because WW II ended in 1945, we used this as marker.Results<: 165 scientists received M&P prizes: 46 in Period A and 119 in Period B (single winners were more common in Period A). Six of 165 (4%) were women, all in Period B. The median age at award was 55 and 52% were between 40-60 years of age. The youngest prize winner was Frederick Banting at 32 (1923) and the oldest were Peyton Rous (1966) and Karl von Frisch (1973)-both 87. 77/165(47%) winners were American citizens, 25 (33%) of were naturalized US citizens. 66/77 (86%) American winners were in Period B. 80% of winners in Period A hailed from European countries including Great Britain and Russia, but only 29% of winners in Period B hailed from these countries. The six M&P awards having a major impact on pediatrics were for works on: serum therapy for diphtheria (von Behring, 1901); immunity(Metchnikoff and Ehrlich, 1908); pertussis (Bordet, 1919); early development of the embryo (Spemann 1935); poliomyelitis virus culture (Enders, Robbins, and Weller, 1954); and genes controlling early embryonic development (Lewis, Nusslein-Volhard and Wieschaus, 1995). Although all prize-winning scientists were of exceptional caliber, some discoveries did not stand the test of time: phototherapy for tuberculosis (Finsen 1903); artificial induction of cancer(Fibiger 1926); fever therapy using malaria infection for neurosyphilis(Wagner-Jauregg, 1927); and lobectomy for personality disorders (Egas Moniz and Hess, 1949). However, the awards made for pediatric topics have had lasting impact. Three Nobel laureates, Thomas Weller, Frederick Robbins (both 1954), and Carlton Gajdusek (1976), had received formal pediatric training. We will present an historical perspective on the prize-winning discoveries which had major impact on the growth of pediatrics.