This quantitative study investigated reasons that school principals recommend non-renewal of probationary teachers' contracts. Principals in the Southeast and Midwest completed an emailed survey. The ordinal nature of the data gathered dictated that comparisons be made between groups using the Mann Whitney U. The study investigated the barriers that work against principals addressing ineffective teaching. Results indicated that principals from both regions are more willing to initiate contract non-renewal when there has been an ethical violation or inappropriate conduct. Principals from both regions reported that teacher instructional skills are more important than subject content knowledge and dispositions in teacher contract non renewals. Vast differences in response by region were found, however as Midwestern principals strongly identified the following barriers: "teacher union," "high cost of litigation," "laws protecting teachers," "collective bargaining agreement," and "desire to avoid conflict and confrontation." Both regions identified "time" as a barrier. (Contains 12 tables and 9 footnotes.)