We studied reproductive parameters and noted predation of Phrynops geoffroanus nests along the Guaporé River of the Brazilian and Bolivian Amazon during the beginning of the falling water level season (vazante) in July 1989 and 2008. We searched for nests on the banks of the Guaporé River every morning navigating by outboard along the Guaporé River between Divisa sector state of Rondônia in Brazil and Versalles village, Department El Beni in Bolivia. We found 10 nests in 1989 and 46 nests in 2008. Clutch size ranged from 7 to 16 eggs and was larger in 2008. There was no relationship between egg size and nest size or the size of eggs between year 1989 and year 2008. The predation rate in 2008 was 89.1%, all depredated by the lizard Tupinambis teguxin. Habitat loss for the lizard may be creating habitat utilization shifting and increased turtle nest depredation rates.