In the light of limited health resources, efficient and effective management of health care system including Primary Health Care (PHC) is necessary. Information is identified as one of the key elements and much attention was given to improve information system management. With effective management of health information system, it is anticipated that PHC managers will be able to efficiently use informationn to support their operational management. This study is an intervention study using microcomputer as a tool to improve health information system at district level. The main objective is to find out whether the microcomputer can be used in health information system, especially for reduction of time spending in information tasks. Expanded Programme of Immunization (EPI) and Family Planning Programme (FP) were selected as the model of study. The study was conducted at Pua district, Nan province in the Northern Region of Thailand. Five out of ten health centers were used as the stusy site. The community hospital at PUA district was used as the center of district health information system. Baseline data related to EPI and Family Planning activities were collected from the sample health centers. Database management systems, dBase III plus, was the application software implemented for data storage and feedback information from center of health information system (at the community hospital) to health centers. Time consuming for information tasks called "total infaormation time" were observed before and after the use of microcomputer and these period of time were used as the indicator to show how effective the microcomputer could reduce working hours in information task. The result showed that in EPI work, "total information time" was reduced from 494.9-697.9 minutes (596.4 (+)(,-)101.5) to 324-452.8 minuters (388.4(+)(,-)64.4) with statistical significance ( p <0.05) and in Pamily Planning work, "Total information time" was reduce from 41.7 - 57.5 minutes (49.6(+)(,-)7.9) to 22.3 - 31.3 minutes (26.8(+)(,-)4.5) with statistical significance (p<0.05). The reduction of time was not as outstanding as expected. The unacquaintance of health personnel to this new technology possibley explained the results. This study, however, demonstrate the feasibility to set up a district health information system community hospital.