Introduction: Poor User Interface design can be one of the probable reasons of users’ error and reduced incentive in using health information systems such as PACS. Heuristic evaluation is one the methods for assuring the proper user interface design of health information systems such as PACS.
Method: This study was a descriptive-analytic research conducted in 2019 through using Nielsen usability checklist. The study setting was Zanjan University of Medical Sciences and data were analyzed in SPSS 25 using descriptive statistics.
Results: In whole, 130 problems were found in 293 usability cases. The most common usability problems include privacy (66.66%), Visibility of System Status (65.52%), and Flexibility and Minimalist Design (60%) and the lowest number of UI design problems were associated with the Pleasurable and Respectful Interaction with the User (14.29%).
Conclusion: Usability Evaluation can identify the reasons of problems that may cause medical errors or users' resistance in working with the system. Therefore, it is necessary for system developers whose systems are widely used in important centers to pay more attention to all standards in designing the system and to prevent the occurrence of errors.