The goal of this study was to quantify marine turtle nesting activity by species, identify threats to their populations, and provide recommendations for their conservation on the south-east coast of Nicaragua. One survey was conducted in each of 1998 and 1999, and 10 surveys in 2000. The majority of nesting emergences were by leatherback Dermochelys coriacea and hawksbill Eretmochelys imbricata turtles, with some nesting also by green turtles Chelonia mydas. In 2000, egg poaching was highest for green turtle (83%) and hawksbill (75%) clutches. A total of 87 dead stranded turtles were encountered, of which at least 63.2% were green, 10.3% hawksbill, and 6.9% loggerhead turtles. The principal threats to marine turtle populations on the south-east coast of Nicaragua were the killing of nesting females, egg poaching, and bycatch in commercial and artisanal fisheries.