Little is known about the nesting ecology of the east Pacific green sea turtle (Chelonia mydas) in Costa Rica. Therefore, this project has been worked in Naranjo beach, over the past three seasons to generate baseline information for this specie. This information is essential to assess the status of the population in the North Pacific of Costa Rica; as part of this project we have partnered with monitoring projects at Cabuyal and Nancite beaches, which are adjacent to Naranjo beach. The supplementary work is essential, since we have determined that nesting females exchange beaches in the area. Thus, our ancillary work has contributed to a more accurate estimate of the population size in this region of the country. Additionally, the project has documented major green turtle predation by jaguars, which hunt females during the process of nest building, egg laying and camouflaging the nest. Finally, the project has significantly contributed to the environmental education program of the National Park, so the rangers, tourists and volunteers are aware of aspects of the biology and conservation of sea turtles. This work will serve as inputs for better planning recovery actions of green turtles in the eastern Pacific.