Firearm-related violence is a significant public health and public safety problem for cities in the USA, and licensed firearm retailers are an important source of the guns used in that violence. Using a scripted telephone interview, we screened a sample of licensed retailers in California to assess their willingness to participate in the surrogate or "straw" purchase of a handgun; such purchases are illegal under federal law. Of 149 retailers who provided a response, 30 (20.1%) agreed to participate. In multivariate analysis, pawnbrokers were more likely to agree than were gun dealers (odds ratio 6.58, 95% confidence interval 1.99-21.71). Sales of handguns that were later subjected to ownership tracing (a proxy measure for a gun's use in crime) were not more frequent among retailers who agreed to participate than among others, and other findings were unexpected as well.