Introduction: Health care professionals must have access to up to date, accurate medicine information in order to use them effectively and safely in patients care. Pharmacy information system is one of the most useful clinical information system a it’s key role in increasing of effectively and efficiency of pharmacy services and in quality improvement in drug therapy, This research was aimed to study pharmacy Information System in Hospitals Affiliated to Shahid Beheshti University of Medical Sciences.

Methods: This is a descriptive study for pharmacy information system in above mentioned hospitals. Data were collected by a checklist and via observation. Content validity and reliability of research tools were measured by test-re-test method. Data are presented as descriptive statistics that are limited to cumulative and relative frequency.

Results: Total studied pharmacy information systems were semi-computerized. Data elements of drugs, patients and prescribers databases were entered incomplete in %50.1, %21.9, and %33 of studied hospitals, respectively. Tasks of pharmacy information system were not done in %43.9 of studied hospitals. Processes of hospital pharmacy information system were not done in %60.7 of studied hospitals. Reports of pharmacy information system were not prepared in %33.2 of studied hospitals.

Conclusion: It is necessity to support processes from therapy activity of pharmacy in all of studied hospitals. Application of electronic hardware and software tools for gathering, processing, and distribution of information would increase accuracy and speed carrying activities in pharmacy. Application of these tools improve of performance of pharmacies in studied hospitals.