The issue of school leadership instability and how it affects schools and student achievement has been studied. The question of how to predict turnover of the principal remains an unknown. The purpose of this research was to search for possible relationships between certain contextual variables and principal turnover and to test the independent variables as predictors of principal turnover frequency. The study reported here focused on the frequency of principal turnover. The term "principal turnover frequency" refers to the frequency with which principals in Ohio public schools were replaced over a seven-year time span. A multiple stepwise regression equation was used to predict principal turnover frequency from the eight contextual variables and an analysis of variance (ANOVA) tested the statistical significance of the variance accounted for in principal turnover by these variables. Seven years of school data from FY1997 to FY2003 were analyzed. Findings indicated that the only predictor variable that was statistically significant in predicting principal turnover was student achievement test scores on Ohio reading and math achievement tests (formerly called proficiency tests) in fourth grade. As the percentage of students who passed fourth grade Ohio reading and math achievement tests increased, the frequency of principal turnover decreased. (Contains 1 figure and 6 tables.)