Introduction: Integrated Hospital Information System (HIS) is vital to decision making and plays a crucial role in the success of the organization. Computerization of the medical records and documentation has resulted in efficient data management and information dissemination for the users. Hospital Information System addresses the entire major functional areas of modern multi-specialty hospitals. The package enables improved patient care, patient safety, efficiency and reduced costs. It provides easy access to critical information, thereby enabling management to make better decisions on time. Aims: The short-term objectives of the on-line computerized system are to reduce costs and improve the accuracy and timeliness of patient care, accounting and administration, record keeping, and management reporting. The long-term goal is to build and maintain patient database for analysis of data to facilitate decision-making process. Methods: To run the system it requires some Hardware & Database for IT Department. The technique involves Patient Registration System, Finance & Accounts, Human Resource Management System, Laboratory, Out Patient Management System, and Inpatient Management System. Results: In the mid seventies, a complex was established at Shahbag area in the name of Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM). From 1982 BIRDEM was designated as the WHO collaborating centre for research on prevention and control of diabetes. It is first of its kind outside Europe. Now from 2000 BIRDEM has successfull developed & implemented some crucial part of HIS System like Patient Admission & Billing System, Finanace & Account System, Human Resourse Management & Payroll System, Store Inventory & Procurement Management System, Labrotary Management System, Assets Management System, Radiology & Imaging Management System. Conclusions: It can thus be seen that deploying IT can help the medical profession in improving its quality of service and thus automatically increasing the preparedness and defensiveness. Of course, it is of vital importance that the software must have the right type of modularity and openness so that it is manageable, maintainable and upgradeable. They can perform the complex task of matching, tabulating, calculating, retrieving, printing and securing the data as required. Well designed, integrated computer system can be a great tool in the hands of the hospital management in improving services, controlling cost, and ensuring optimal utilization of facilities.