Reproductive data on the western cottonmouth, Agkistrodon piscivorus leucostoma, are scarce, generally incomplete, and usually based on pooled years for a given area. Current paradigms suggest that reproductive output in snakes can be influenced by local resource availability so temporal variation is important to document. Pregnant female western cottonmouths were collected for 3 consecutive years (2000–2002) from a lowland hardwood forest in northeastern Texas. This bottomland is exposed to flood pulses during winter that produce variable, but often large, amounts of prey for semi-aquatic snakes. Data recorded from 27 females indicated no difference in their snout-vent lengths (SVL) or masses among years. Of all reproductive traits, only clutch mass was correlated to female SVL and only in 1 year. Clutch mass and relative clutch mass varied temporally, suggesting reproductive output was influenced by prey availability. However, clutch size and mean offspring mass (that together comprise clutch mass) were both consistent among years. There was variation in mean offspring SVL and mass among females, and a negative correlation of both offspring characteristics to clutch size. These results suggest that the reproductive output of individual females might be responding to variation in prey availability in different ways (i.e., some by varying offspring number and others by modifying offspring size). Testing this hypothesis will require monitoring individual females for multiple years.