: The current study examines the effects of a hospital information system (HIS) on the performance of management units in Ahvaz public hospitals, Iran. The HIS supports hospital activities at practical, tactical, and strategic levels. In other words, this system establishes a connection between patient care and administrative information in all hospital activities. This descriptive-analytic research was an applied study with a correlational method. The hypotheses were tested by correlation model, structural equation modeling, one-sample t-test, one-way analysis of variance, and one-sample Kolmogorov-Smirnov test using the SPSS software version 20 and LISREL. The findings of this study indicated that an automated HIS can be a powerful tool helping managers with the process of hospital management and decision-making, leading to significantly improved hospital performance. Therefore, continuous training courses are beneficial in enhancing information quality and modern technology usage, which in turn improve the quality of services offered to patients and clients and make them less time-consuming. As a result, an effective step is taken in improving health services. The present study showed that the characteristics of HIS, including user-friendliness, speed, quality, being up-to-date, conformity with working conditions, and proficiency, have positive and significant impacts on the performance of management units.