Located between the west end of Restinga de Marambaia and Ponta da Juatinga, it has a total area of approximately 174 km².

Its highest point is the Peak of Pedra d’Água, 1,037 m high, however, the most characteristic one is the Peak of the Parrot (Pico do Papagaio), 882 m high, for its similarity with a parrot beak.

The island is occupied, partly, by Parque Estadual da Ilha Grande and it is considered a biological reserve. It is totally covered with tropical forest of dense and exuberant flora and fauna, preserved due to the climatic conditions and to the difficult access to the interior of the island.

The island presents a great number of beaches, both long and short. The inhabitants are spread in small settlements throughout the beaches. The most important one is Vila do Abraão, where the tourists can find a better infrastructure, with some hotels and bars.