Health Information System (HIS) implementations are on the rise in North America as the result of increased investment by governments. According to the evidence, systems not only have the potential to introduce error, but poorly designed user interfaces can result in systems that are not usable and possibly unsafe. Therefore, the need to evaluate HIS during the early phases of the system development lifecycle is becoming increasingly important. Researchers have begun to propose usability engineering methods that can be applied to help evaluate systems during design and development using an iterative evaluation process. A cognitive walkthrough was used to evaluate an Operating Room Management Information Systems' (ORMIS) electronic perioperative documentation. The resulting usability problems are discussed along with recommendations for improvement in this paper.