Five species of sea turtle are known to nest on the north and east coast beaches of Trinidad, West Indies. In descending order of abundance: the leatherback (Dermochelys coriacea), the hawksbill (Eretmochelys imbricata), the green (Chelonia mydas), the olive ridley (Lepidochelys olivacea) and the loggerhead (Caretta caretta). This thesis investigates a number of aspects of the ecology and conservation of the sea turtles nesting and foraging on the north coast. Prior to this project, little research had been carried out on the north coast region, largely due to the difficulties of accessing the nesting beaches. The main aims of the project include making reliable estimates of the annual nesting population size of each species, to identify the main threats to the turtles at various life stages, and to make recommendations on how best to conserve the sea turtles in Trinidad. Overall, this thesis offers an up-to-date overview of the status of the sea turtle populations nesting on the north coast of Trinidad. The results presented here highlight Trinidad’s importance as a region for turtles, especially for nesting leatherbacks, foraging greens and nesting and foraging hawksbills. This study will be useful in assisting the Trinidadian Government to meet their obligations under the Biodiversity Convention, and in facilitating the assessment of the remaining leatherbacks in the Atlantic. Recommendations are made for future conservation and management.