Lean principles and statistical analysis have been successfully implemented to hospitals and healthcare systems. These principles among other process improvement principles aim to detect and eliminate wastes in the system and its processes. In this paper, lean and statistical analysis were applied to systematically investigate the causes of low operating room (OR) block utilization and recommend solutions to improve the utilization. The study was carried out at a tertiary hospital in Pennsylvania. Root cause analysis has identified the main reasons of delays that impact utilization, i.e., waiting in OR after surgery is done due to bed unavailability, delays in preoperative process due to IV insertion difficulty and unavailable beds, and scheduling problems such as late first case starts and unrealistic surgery schedules. Countermeasures were developed, reevaluating the current scheduling practice and developing a scheduling tool are believed to be the best countermeasures in terms of ease of implementation and impact.