This study examined the validity of a single-item measure of HIV risk stage of change that HIV prevention contractors were required to collect by the California State Office of AIDS. The single-item measure was compared to the more conventional University of Rhode Island Change Assessment (URICA). Participants were members of Los Angeles County-defined behavioral risk groups recruited from a mobile HIV testing program (N = 123). The study found low correspondence between participants' stage of change on the single-item and the URICA, suggesting that they do not assess the same construct, and that the single item may not provide a valid measure. The current data suggests that the single-item measure should be revised or abandoned in favor of more conventional stage-of-change measures. (Contains 2 tables.)