The present article is a study of the use of the People Research and Development Method as a means of promoting local wisdom, environmental protection, and community development in Tambon Bangkhunsai, Phetchaburi Province, Thailand. This method allowed the community to do their own research and to utilize their local wisdom as a form of untapped capital on which self-reliance can be built. Research findings indicated that the People Research and Development method could stimulate local wisdom to protect the environmental and develop the community in a number of ways. In particular, the local fishermen employed their local wisdom to collect clams and shellfish. They were able to make their own gear in such a way as not to destroy the natural resources and to ensure the preservation of the natural resources for a long time. Local wisdom was also used in the formation of community development projects such as an eco-tourism group and a processed seafood group. It is anticipated that these projects will lead to sustainable resources management.