This quantitative study investigated reasons that school principals recommend non-renewal of probationary teachers' contracts. Principal survey results from three regions of the US (Midwest, Rocky Mountains, & Southeast) were analyzed using the Kruskal-Wallis and Mann-Whitney U statistical procedures, while significance was tested applying a Bonferroni Correction. The study examined prioritized reasons for teacher contract non-renewal, behaviors observed from ineffective teachers, and complications which work against addressing ineffective teaching. Results indicated that principals from all regions are more willing to initiate contract non-renewals when there have been ethical violations or inappropriate conduct. All regions' principals reported that teacher instructional skills are more important than subject content knowledge and dispositions in teacher contract non-renewals; however Southeastern principals placed more importance on subject content knowledge than their counterparts. All regions' principals strongly identified the barrier of time; whereas only principals from the Midwest and Rocky Mountain identified teacher unions, laws protecting teachers, and collective bargaining agreements as complications to addressing ineffective teachers. (Contains 13 tables and 12 footnotes.)