It seems that many Nobel Prizes were awarded that, in retrospect, were very bad decisions. It looks like the Physics & Chemistry prizes are pretty much free of embarrassment, but the Medicine, Peace, and Economic prizes include many howlers. [The Peace prize to H.Kissinger & Le Duc Tho in 1973 jointly, was amazing (Le Duc Tho actually refused it!) as was its award to B.Obama.] Anyway, here's a list of Medicine prizes: 1904 to Ivan Pavlov re digestion. Unfortunately Pavlov's main discovery was refuted in 1902 by EH Starling & WM Bayliss, and the refutors by discovering the first hormone, "secretin," actually accomplished something far more important (as well as correct this time), but they didn't get a prize... 1923 to Banting & Macleod for discovering the existence of insulin. But in 1962 the Nobel prize committee announced it had made a mistake since "Macleod had taken no active part in the work." 1926 to Johannes Fibiger for "discovering" that the cause of cancer was worms. He was totally wrong. 1927 to J.Wagner-Jauregg for "curing" dementia caused by syphilis by intentionally infecting patients with malaria. The patients that he cured, were defined to be cured, by him. 1949 to Antonio Egas Moniz for inventing the "revolutionary therapy" of lobotomy, aka intentional brain mutilation. (Which also was later used to "cure homosexuals.") 1952 to Selman Waksman for discovering streptomycin. Actually it was Albert Schatz, a doctoral student of SW's. They both were credited as discoverers on US patent and Schatz was 1st author of the paper, but Waksman grabbed all the royalties of about $350K in secret while giving Schatz essentially nothing (a "gift" of $1500) plus explained that Schatz had nothing to do with it and was only included on the paper & patent as a "courtesy." There then was a lawsuit, and Schatz was recognized as co-discover and awarded a 3:10 split of royalties with Waksman. This all happened before the Nobel award. 1997 Stanley B. Prusiner for "prions" and diseases they cause. However there remains some substantial fraction of scientists who do not believe prions really exist, so let's hope the Nobel Prize committee got this right. The prion detractors feel that the Award may have shut down anti-prion research, which, if prions really do not exist, was a very bad thing. It's very hard to prove it was prions and not anything else, and Prusiner's proof was necessarily not very convincing. However, based on this 2004 paper http://www.ncbi.nlm.nih.gov/pubmed/15286374 and several followup papers, where they synthesized prion protein than showed it caused disease, I think Prusiner must have been correct. So the Nobel committee got lucky on this one!