Concerns about effective use of school instructional time have been evident for many years. The more stringent demands of the newer accountability mechanisms have obligated educators to renew efforts to optimize the teaching and learning process. This study addressed the nature and extent of classroom instructional time erosion by external intrusion. More than 200 principals and assistant principals in 149 schools and 12 Louisiana school districts participated in a self-administered survey. The results indicate that encroachment upon instructional time remains problematic in many schools and that the leadership to adequately address the circumstance may be lacking. (Contains 3 tables.)