Problem. Some Catholic schools report high teacher attrition rates. Understanding reasons for teacher attrition and responding to those issues is one of the many responsibilities of principals. However, it is unclear what Catholic principals understand about teacher attrition. Ingersoll's extensive research on teacher attrition has provided a useful theoretical framework by which to understand some of the reasons for teacher attrition in private schools, but it is unclear if these apply to Indiana Catholic schools. This study examined principals' perceptions of teacher attrition in Indiana Catholic schools and then checked for agreement with Ingersoll's theoretical framework on teacher attrition in private schools. Method. An online survey asked Indiana Catholic school principals their perceptions of the direction of attrition for 18 of Ingersoll's teacher attrition elements in private schools. One-hundred and twenty-two out of 173 principals responded. Ingersoll's elements were used to create 18 research hypotheses that checked to see if principals would agree with Ingersoll's predicted direction of teacher attrition for the assigned elements. Chi-square tests of independence determined whether principals significantly agreed with Ingersoll. The survey also asked for information about principals' characteristics (ethnicity, experience, gender, and staff category) and characteristics of principals' schools (enrollment, grade levels, location of schools, and school sponsors). Linear regression tests determined if there were significant relationships between principal and school characteristics and principals' agreement with Ingersoll's predicted direction of teacher attrition for each element. Results. Ingersoll's theoretical framework was useful in understanding Indiana Catholic school principals' perceptions of teacher attrition. Even when principals disagreed with Ingersoll's findings, there was general agreement with his teacher attrition constructs. Principals significantly agreed with Ingersoll's predicted direction of teacher attrition for 7 of the 18 elements (younger, special-education, male, rural, higher salary, lack of administrative support, and lack of faculty influence). For 2 of the 18 elements, principals' perceptions were significant but not in agreement with Ingersoll (older and minority). Principals at larger schools were significantly more likely to agree with Ingersoll that male teachers have higher attrition rates than female teachers. Principals at parish-sponsored schools were significantly more likely to agree with Ingersoll that teachers with higher salaries had lower attrition rates than teachers with lower salaries. Finally, principals at schools sponsored by multiple parishes were significantly more likely to agree with Ingersoll that teachers with a lack of faculty influence had higher attrition rates than teachers with faculty influence. Of these findings, three stood out. Indiana Catholic school principals perceived the annual attrition rate for teachers in Indiana Catholic schools was lower than the national public and private school averages. Principals perceived older teachers had significantly lower attrition rates than do middle-age teachers, which did not agree with Ingersoll's findings. Principals' perceptions of teacher attrition rates for minority teachers were significant (in the same range), but not significantly higher than nonminority teachers, which did not agree with Ingersoll's findings. One of the contributions of this study was to estimate the stability of Ingersoll's theoretical framework for the subpopulation of Indiana Catholic school principals. Ingersoll's elements were stable for 7 of his 18 elements and for non-unionized Indiana Catholic schools. Conclusions. Ingersoll's theoretical framework on teacher attrition was useful to Indiana Catholic school principals as it provided a common ground to assess teacher attrition in private schools. Principals may wish to review Ingersoll's predicted direction of teacher attrition elements to guide their own understanding of what is happening with teacher attrition in Catholic schools. This increased knowledge about teacher attrition could better equip Indiana Catholic school principals to retain more teachers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]