Avian cholera was diagnosed in lesser snow geese (Anser c. caerulescens), Ross' geese (Anser rossii) and individuals of several other waterfowl species in a small area of south-western Saskatchewan over a 1 month period during the 1977 spring migration. Approximately 250 dead birds were found. This is apparently the first time avian cholera has been reported in migrating waterfowl in Canada. The site of the mortality was midway between the wintering and nesting areas of the two principal species, and the significance of the occurrence of the disease this far north is discussed.