In this paper, besides general information some new developments concerning botulism, the causative agent C. botulinum and the botulinum toxin are discussed. At the moment, three different disease models are distinguished according to the pathogenesis, viz: a) the classical food-borne botulism caused by preformed toxin, b) wound botulism and, since 1976, c) infant botulism. The pathogenesis of infant botulism is not yet sufficiently elucidated so far, all cases have been found in the U.S.A. except single ones in England and Australia (Center for Disease Control, 1979). The diagnosis is based on clinical symptoms and the demonstration of botulinum toxin. The isolation of C. botulinum is helpful but has no decisive diagnostic value. The risk of botulism exists wherever the incidence of C. botulinum in soil is high. In man, foodborne botulism is caused by carelessness in the preparation and preservation of vegetable and animal foods. The disease is mainly recorded in the Northern Hemisphere. In animals botulism has been diagnosed in all parts of the world, mainly in horses, ruminants, mink and many bird species. C. botulinum is widely distributed in the soil and in water, but the degree of infection may differ from one area to another and, moreOver, the distribution of the different toxin types may vary greatly. Knowledge on the situation in Asia, Africa and South America is scarce. However, this knowledge is of growing significance because food processors are increasingly using products from those parts of the world. From four European countries more extensive data on the presence of C. botulinum spores are available (Table 1). It is obvious that type A occurs very sporadically, in contrast to the situation in North America. The number of positive cultures was low in Russia, in Great Britain type B was most frequently detected, in the Netherlands type C and in Sweden type E. However, at least in the Netherlands the distribution of the various toxin types is highly influenced by the types of material and ecosystems which are investigated (Table 2). On the other hand, when the same areas were investigated for 3 consecutive years it was found that the distribution of the C. botulinum types was rather stable (Table 3). The isolation of pure cultures can only be persued in special cases, but this isolation is necessary in order to obtain a better insight into the properties of the prevalent C. botulinum strains, and thus to know. e.g., whether proteolytic or nonproteolytic strains are present. In Europe only nonproteolytic