The retreat of Wurtenkees, a glacier of about 1 km2 in the European East Alps, is described by measurement of frontal change, interpretation of maps and a computed mass-balance series. Since 1850, Wurtenkees has been one of the most strongly retreating glaciers in this region. Mass balance has been measured since 1982. Measured values of the accumulation area ratio and the equilibrium-line altitude as well as a degree-days model are used for the description of the activity conditions of the glacier. Under present climatic conditions Wurtenkees would need a lowering of the mean air temperature during the summer season of 1–1.5° C to return to a balanced mass budget. With predicted global warming, the glacier is likely to disappear early in the 21st century.