Membership in scientific societies is an avenue wildlife professionals may use to maintain and enhance their professional capabilities. We studied factors influencing United States Fish and Wildlife Service (USFWS) and United States Geological Survey (USGS) biologists' membership in scientific societies in general and The Wildlife Society (TWS) in particular. We conducted an internet census survey of 3,755 USFWS professionals and 932 USGS Biological Resource Division professionals. The survey collected data on membership and participation in scientific societies as well as other variables that we theorized could influence membership. We used logistic regressions to identify factors correlated with the membership of wildlife biologists in TWS. A greater proportion of USGS biologists (90.2%) than USFWS biologists (51.8%) were members of scientific societies, and the likelihood of wildlife biologists belonging to TWS was higher in USGS. Factors most consistently correlated with membership in TWS included minimal external constraints (e.g., family responsibilities and costs), supervisor support for membership, and membership of friends, peers, and supervisors in scientific societies. Our results suggest that membership in scientific societies is heavily influenced by the organizational culture of employing agencies. Agencies seeking to increase their employees' membership, and thus benefits from participation, in scientific societies will be most successful if they create a culture in which involvement in scientific societies is expected and in which peers and supervisors also participate.