ABSTRACTWe ascertained various life-history traits from an examination of 310 museum specimens of the Rio Grande leopard frog (Lithobates berlandieri) collected during 1907–2016 from Texas, USA. Lithobates berlandieri was captured during every month of the year except November, and adults were most frequently encountered during January–September, with a distinct peak in May. Mean body size of adult males (69.5 mm) was smaller than that of adult females (77.5 mm), and adult body sizes tended to be smaller at higher latitudes, a trend that was more pronounced in males. Females were gravid during January–September, and most gravid females were captured from late winter to early summer. Gonadal enlargement in males was generally high throughout January–September with no detectable seasonal increase. Feeding became widespread in both sexes during May–June shortly after a spring breeding bout. Spent females (ovarian stage 1) were common in July and lipid deposition increased in June/July, signalling oogenesis for breeding in the fall. From 15 gravid females, we estimated a mean clutch size of 3107 eggs which was correlated with female body size, yet egg diameter was not related to clutch or body size. Age to metamorphosis was likely 2–4 months depending upon whether eggs were laid in the winter/spring or late fall. If metamorphosis occurred in May/June, the minimum size at sexual maturity could have been reached in 7–8 months for adult males (50.1 mm) and in 9–10 months for adult females (57.2 mm). Mean adult body sizes, however, may have taken 14 to 17 months to reach. A synthesis across Texas populations suggests that the breeding season extends almost continuously from the fall through the winter and spring until mid-summer and is interrupted by extreme temperatures in the winter and summer.