2009
- Biology: Fumiaki Taguchi, Song Guofu, and Zhang Guanglei of Kitasato University Graduate School of Medical Sciences in Sagamihara, Japan, for demonstrating that kitchen refuse can be reduced more than 90% in mass by using bacteria extracted from the feces of giant pandas.
- Chemistry: Javier Morales, Miguel Apatiga, and Victor M. Castano of Universidad Nacional Autonoma de Mexico, for creating diamond film from tequila.
- Economics: The directors, executives, and auditors of four Icelandic banks—Kaupthing Bank, Landsbanki, Glitnir Bank, and Central Bank of Iceland—for demonstrating that tiny banks can be rapidly transformed into huge banks, and vice versa (and for demonstrating that similar things can be done to an entire national economy).
- Literature: Ireland's police service for writing and presenting more than 50 traffic tickets to a Polish individual, by the name of "Prawo Jazdy". Mr. "Jazdy" was widely thought to be the most frequent driving offender in Ireland, until an investigation uncovered the fact that Prawo Jazdy is the Polish term for "Driving License".
- Mathematics: Gideon Gono, governor of Zimbabwe's Reserve Bank, for giving people a simple, everyday way to cope with a wide range of numbers by having his bank print notes with denominations ranging from one cent to one hundred trillion dollars.
- Medicine: Donald L. Unger of Thousand Oaks, California, US, for investigating a possible cause of arthritis of the fingers, by diligently cracking the knuckles of his left hand but not his right hand every day for 50 years.
- Peace: Stephan Bolliger, Steffen Ross, Lars Oesterhelweg, Michael Thali, and Beat Kneubuehl of the University of Bern, Switzerland, for determining whether it is better to be hit on the head with a full bottle of beer or with an empty bottle.
- Physics: Katherine K. Whitcome of the University of Cincinnati, Daniel E Lieberman of Harvard University, and Liza J. Shapiro of the University of Texas at Austin, all in the US, for analytically determining why pregnant women do not tip over.
- Public Health: Elena N. Bodnar, Raphael C. Lee, and Sandra Marijan of Chicago, US, for inventing a bra that can be quickly converted into a pair of gas masks—one for the wearer and one to be given to a needy bystander.
- Veterinary medicine: Catherine Douglas and Peter Rowlinson of Newcastle University, UK, for showing that cows with names give more milk than cows that are nameless.
Read more about this topic: List Of Ig Nobel Prize Winners