This study examines the utility of systematically accounting for acceptable physician variations in guideline application. The results argue against assuming that even seemingly noncontentious guideline protocol offer a threshold of variation similar to conventional Continuous Quality Improvement (CQI) assessment standards. Findings also suggest that health service organizations can derive greater benefits from expending the resources necessary to standardize guidelines if compliance with both the medical review criteria, and the guidelines as originally constructed, is monitored as part of the evaluation activity.