Since 1968, he was the head of a research group concentrating on methodological developments in liquid state and solid state NMR. He developed two-dimensional NMR and many novel pulse techniques. Ernst contributed to the development of medical magnetic resonance tomography and, in collaboration with Professor Kurt Wüthrich, to the development of the NMR structure determination of biopolymers in solution. Lately, he was involved in the study of intramolecular dynamics.
Ernst was president of the Research Council of ETH Zurich. He was a member of the Swiss Science Council, the COST Committee, the Foundation Marcel Benoist, the Hochschulrat, the Technische Universität Munich, and vice president of the board of Bruker AG, Fällanden. He is also on the editorial board of ten scientific journals.
Ernst received numerous honors, including the Nobel Prize for Chemistry in 1991, the Wolf Prize for Chemistry in 1991, the Horwitz Prize in 1991, and the Marcel Benoist Prize in 1986. He received honorary doctoral degrees from ETH Lausanne, Technische Universität Munich, Universität Zurich, University Antwerpen, Babes-Bolyai University in Romania, University Montpellier, Charles University in Prague, University of Allahabad in India, King George University in India, KIIT University in Bhubaneswar, Ricardo Palma University in Peru, and Universidad Nacional de Cordoba in Argentina.
He is a member of the U.S. National Academy of Sciences, the U.K. Royal Academy of Sciences, the Deutsche Akademie Leopoldina, the Russian Academy of Sciences, the Korean Academy of Science and Technology, and honorary member of many other societies. Today, Ernst is involved in the studies and conservation of central Asian art. He became active also in Raman spectroscopy for identifying pigments in ancient paintings.