This book is a review of the literature on Gnathostoma infections of animals and man in Thailand, including relevant information published in other countries. The author regards 12 species of Gnathostoma as being valid (22 have been described) but he only deals with the 4 known as mature parasites from vertebrate definitive hosts in Thailand. The 4 species (each dealt with in a separate chapter) are G. spinigerum, G. hispidum, G. doloresi and G. vietnamicum and knowledge of their distribution, morphology and life-cycle is reviewed, together with information (where available) on pathogenicity, diagnosis, treatment and prevention. Most is known about G. spinigerum which is the cause of virtually all the cases of gnathostomiasis reported in humans. Other definitive hosts include dogs and cats. The first intermediate host is cyclops and the 2nd intermediate hosts are a wide variety of vertebrates. Uncooked fish is a common source of human infection. G. hispidum and G. doloresi mature in the stomach of pigs and wild boars; only 2 human cases (both with G. hispidum) have been reported. G. vietnamicum is a parasite of the otter. The author of this book is an authority on gnathostomiasis, having published many papers on the subject, going back as far as 1933. His efforts in compiling this book will be welcomed by everyone interested in gnathostomiasis, mostly by those in Thailand and other parts of Asia, but also in other countries where the genus occurs.