Nest-site selection by female Trachemys callirostris callirostris was studied on an island in the Pijiño wetland of the Mompos Depression of Colombia. We quantified distances of nests to the shoreline and compared vegetative cover and soil types at nest locations and at randomly selected points on the island. Nests sites were concentrated in the first 5 m from the shoreline and were always located under vegetative cover. Such cover might reduce thermal stress to nesting females, lower the probability of nest detection by predators, and buffer the incubating eggs from environmental extremes. Females preferentially nested under water hyacinth, but it was not clear whether they selected directly for this vegetative cover type or simply preferred dirt substrates where it dominated, because dirt soils contained higher humidity.