Background and Aim: Health information System (HIS) is a comprehensive software used to unify and transfer hospital data effectively. It is vastly employed to improve input quality, decrease data-transfer time, increase satisfaction level, promote health services quality, and minimize hospital costs.

Materials and Methods: This is an applied-descriptive study. The research population consisted of 120 HIS users who worked before and after the HIS application at Masih-Daneshvari Hospital. For data collection purposes, a questionnaire was used. The data were then analyzed with SPSS software, and descriptive and inferential statistical methods.

Results: According to data analysis, the application of the existing communication system among the different sections and wards was very good (81%), the accessibility to patient medical information and facilitating treatment processes were good (44% and 61%, respectively), and the analysis of budgeting data (11%), the possibility of clinical researches (19%), the presentation of guides for operators (18%), and the accessibility to statistical and financial data (17% and 22%, respectively) were assessed as poor.

Conclusion: The results of this survey show that the application of Hospital Information System has a positive effect on accuracy, facility, and treatment processes, and emphasize the importance of programming to enhance the quality of hospital services.