Von Bertalanffy growth-curve parameters were calculated from plastral annuli of specimens of Graptemys ouachitensis and G. pseudogeographica kohnii captured in western Kentucky, and museum specimens of G. ernsti from Alabama and G. caglei (males only) from Texas. Males had estimated values of k (intrinsic rate of growth toward asymptotic plastron length, PL_A) ranging from 0.264 to 0.498. Values of k for females of three species (range 0.110–0.182) were significantly less than the corresponding values for males, whereas PL_A values for females (range 175.3–220.2 mm) greatly exceeded PL_A values of males (range 91.5–114.5 mm). There was a significant negative correlation of PL_A with k within 13 emydid turtle populations for which von Bertalanffy parameter estimates were available, with a slope similar to those reported for fish taxa; however, this relationship was not evident for either male values or female values when data were analyzed by phylogenetically independent contrasts. Use of the Richards model, a parent growth curve to the von Bertalanffy model, improved model fit for only one of seven data sets, whereas use of sine-wave versions of the von Bertalanffy and Richards models improved model fit for only two of seven data sets.