A total of 177 residents in two Mexican cities responded to an instrument assessing (a) personal normative beliefs about water conservation, (b) beliefs about the efficacy of water conservation laws, (c) the tendency to break social norms (antisocial behavior), and (d) private water conservation behavior (self-reported). The data were processed within a structural equation model that specified the above effects. Results showed that personal normative beliefs had a positive effect on water conservation, whereas antisocial behavior inhibited that conservation, and beliefs in the inefficacy of water conservation laws produced no effect on water conservation practices. Significant and negative covariances between antisocial behavior and normative beliefs and between antisocial behavior and beliefs in the inefficacy of water consumption laws resulted. Conversely, normative beliefs and beliefs in the inefficacy of water laws covaried positively.