Freshwater turtles are appropriate organisms for studying maternal investment in offspring because, unlike most long-lived vertebrates, turtles show high fecundities and most provide no parental care. We studied reproductive patterns of two emydine freshwater turtle species, the Texas river cooter (Pseudemys texana) and the red-eared slider (Trachemys scripta elegans) at Spring Lake, Hays County, Texas during the 2009 nesting season. Forty-six percent of all nesting Texas river cooters and 25% of all nesting red-eared sliders nested twice, with some Texas river cooters nesting more than twice. Mean egg mass, egg length, and egg width decreased in subsequent clutches in Texas river cooters. However, there was an insufficient sample size of subsequent clutches (n = 6) to draw conclusions for red-eared sliders. Red-eared sliders did not show a positive relationship between clutch size and body size. We found that in both species there was a positive relationship between egg width and egg mass in relation to maternal body size. However, only Texas river cooters showed a positive relationship between clutch size and maternal size, while only red-eared sliders showed a positive relationship between egg length and maternal size. By comparing reproductive parameters of these two coexisting populations, we concluded that the members of these two species allocate resources differently for reproduction.