Tenure policies for elementary and secondary school teachers is a controversial issue in many states, but there is virtually no empirical evidence on how tenure affects teacher labor markets. This paper begins to fill this research void by using cross-state variation in tenure policies to identify the effects, if any, of the length of the probationary period on entry-level teacher salaries. Using data from the Schools and Staffing Survey, the authors investigate whether districts in states with longer probationary periods offer higher wages to teachers as a way to compensate for the extended evaluative period. Results suggest that they do, although effects are concentrated in districts that are most likely to be competing for teachers with districts in neighboring states with shorter probation periods. The authors also find that the relationship between probation length and wages is stronger for experienced teachers and in districts that engage in collective bargaining.