Building on the success of the Thai-German Rodent Control Project, the Thai-German Plant Protection Project continued Thai-German technical cooperation with the Thai Ministry of Agriculture and Cooperatives (Department of Agriculture & Department of Agricultural Extension) within the broader framework of general plant protection. It aimed at fostering the economically based use of plant protection measures for the increase of agricultural production under special consideration of environmental effects and social cost. To this end a variety of measures were conducted in different fields, including integrated plant protection, residue control, research, and control of vertebrates, snails and crayfish. A monitoring and early warning system was introduced into the 30 Plant Protection Service Units on province-level and 9 “plant clinics” were supported and promoted by the qualification of their personnel. The project furthermore succeeded in establishing the organizational and technological prerequisites for effective plant protection with the two partner organizations. Therewith long-term positive impacts such as economic benefit for individual farmers by higher yields and saving expenses for pesticides and fewer residues in food (protection of the environment and health of consumers) could be expected at the end of the project’s duration.