"We estimated the distribution and abundance of the Central American River Turtle, Dermatemys mawii, in four aquatic systems in southern Quintana Roo, Mexico. Using nets and free diving we captured 52 individuals D. mawii among the winter, dry and rainy seasons. We recorded 12 variables to characterize the habitat and correlated these with the abundance of D. mawii. Using catching per unit effort, we evaluated the species’ relative abundance for each aquatic system. Using Maxent, we modeled the potential distribution of D. mawii using historical and present locality data. We recorded 81 D. mawii individuals using systematic sampling and casual observations. La Union was the site with the highest relative abundance (~4 ind.-net). We found a negative correlation between D. mawii abundance and salinity. The model of potential distribution identified sites with ecological conditions suitable for the species where it is undocumented. Information about the ecology of this species remains scarce, but we propose that identifying management units could improve conservation of the species at local and regional levels."