Thailand's fishing industry is one of the world's ten largest, with a fleet of 20,000 modern vessels and an annual catch of about 2 million tons of fish, but the Thai government's ability to manage the fishing industry has not kept pace. In fact, the rapid development of the Thai trawl fishery and concomitant stagnation of the small-scale coastal fishery have resulted in a dualistic structure - small-scale fisheries employ over 70% of fishermen, but land less than 30% of the total catch. This study documents the profitability of trawl fishing, the poverty of small-scale fishermen, the heavy overfishing of the Gulf of Thailand, and the discrepancy between the catching power of the Thai fishing industry and the management and enforcement capabilities of Thailand and its neighbors. The study concludes that actions to resolve Thailand's fisheries problems would involve (1) an immediate halt to the construction of new trawlers and stricter controls on existing vessels, in order to curtail destructive in-shore fishing and illicit distant-water operations; and (2) fisheries enhancement projects for small- and large-scale fishermen (e.g., artificial reefs, joint ventures with neighboring countries); and (3) the development of alternative sources of employment and animal protein. Includes tables and references (1953-85). (Author abstract, modified).