The authors draw on strategic human resource and industrial relations theories to identify the sets of employee voice mechanisms and human resource practices that are likely to predict firm-level quit rates, then empirically evaluate the predictive power of these variables using data from a 1998 establishment level survey in the telecommunications industry. With respect to alternative voice mechanisms, they find that union representation predicts lower quit rates, even after they control for compensation and a wide range of other human resource practices that may be affected by collective bargaining. Also predicting lower quit rates is employee participation in offline problem-solving groups and in self-directed teams. No apparent association is found between quit rates and the availability of nonunion dispute resolution procedures. Regarding human resource practices, higher relative wages and internal promotion policies predict lower quit rates, and contingent staffing, electronic monitoring, and variable pay predict higher rates.