Enterotoxaemia in sheep due to Clostridium welchii type D was indicated by field and laboratory investigations in Nepal. Morphological, cultural, biochemical, biological and toxin-producing characteristics observed were used to type the isolates. In anaerobic meat medium, all isolates produced pinkish discoloration of meat. All the strains fermented lactose, maltose, dextrose and sucrose whereas, salicine was fermented only by 17 strains. All but five strains were MR negative. Out of 200 isolated, 166 produced both alpha and epsilon toxins and the remaining 34 non-toxogenic strains are likely to be variants which have lost their toxogenicity. Epidemiologically the local name "Six months disease" and enterotoxaemia are considered to be identical diseases.