The study documented the process and outcomes of 30 grievances in the participating school districts in the course of a school calendar year. Fifteen grievances were referred to mediation, and 15 were submitted to arbitration. Of the 15 grievances referred to mediation, 11 were settled through the mediation conference; 2 were unresolved but subsequently decided in artibtration; and 2 were unresolved, but were neither scheduled for arbitration nor withdrawn. Grievances referred to mediation prior to arbitration were resolved faster, less expensively, and in less time than grievances resolved in arbitration. Union advocates had greater satisfaction with the substantive aspects of mediation than with the same aspects of arbitration. Mediation's greater ability to deal with the problem underlying the grievance was a major advantage over arbitration. The large majority of all participants in a mediation conference or an arbitration hearing preferred mediation as a step prior to arbitration rather than mediation only or arbitration only. 11 tables, 1 figure, and an appended experimental agreement for the mediation of grievances.