Caste-based Hindu coastal fishers of Bangladesh have developed their Traditional Ecological Knowledge (TEK), environment and resource friendly practices, and worldviews through years of social learning, and interaction with their immediate ecosystem. This article is based on 21-month long participatory field research with the fishers of Thakurtala fishing village, Moheskhali Island, Cox’sbazar district, located along the Bay of Bengal. Eight important categories of fishers’ TEK systems are examined: water color, wind direction and current, lunar periodicity, sediment and topography, celestial navigation, birds and animals, mangroves, and fishing sites. Fishers make their decisions about fishing at a certain site using practical heuristic rules. The sequence of learning and transmission of TEK at different age strata is examined. Policy makers would benefit from TEK of the experienced coastal fishers.