Although the ecology of the Gulf Coast waterdog, Necturus beyeri, has been studied in Louisiana, there is no information on eastern Texas populations. We document the seasonal activity and individual movements of this species in Smith County, Texas. Minnow traps were placed at 10-m intervals in Gilley Creek from 1996 to 1999 (20 total) and in Hill Creek in 2002–2003 (75 total) and checked once per week. Animals captured were sexed, measured, weighed, and tagged with PIT tags. Seasonal activity was determined from the number captured per month, and individual movements were based on distances moved between captures. Gulf Coast waterdogs in eastern Texas were active from October to March, generally moving only short distances. Occasionally, long distance movements were made, but these animals often returned to the initial capture site. Our results suggest that Gulf Coast waterdogs in eastern Texas behave much like those in southern Louisiana.