This report gives an update on a population of nesting females of green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles from August 2000 to December 2004 at Nosy Iranja Kely (North West Madagascar), one of the two islands of the Iranja Archipelago. Monitoring of marine turtles on this island was possible because of cooperation between a private hotel and researchers. As in the majority of turtle nesting sites in the South West Indian Ocean, the green turtle is the most abundant marine turtle species nesting in Nosy Iranja Kely. From August 2000 to December 2004, 345 green turtle nests were recorded, while only 76, hawksbill turtle nests were found. The nesting period for both species is seasonal: green turtle nesting peaking during the winter months (May to August) and hawksbill during the summer months (December to March). This monitoring also emphasizes the importance of the island for hawksbill nesting as this species nest is rare in the Comoros Basin. While tourist activities may have had a negative impact on marine turtles on the east of the island, these activities also have a positive impact on the south, helping to reduce threats such as poaching and allow an effective monitoring of nesting marine turtles on the island.