Health information systems (HIS) play a major role in decision-making. The aim of this study is to identify the components of computerized HIS and their relationship to medical and administrative decisions at the main referral hospitals for Sana'a city. It is a descriptive, cross-sectional study in which the HIS of 7 hospitals affiliated with Sana'a city hospitals during "2017-2020". Data were collected by using Self-administered questionnaires and analyzed in SPSS 16 by using descriptive statistics. A total of 626 users (95.7%) responded. 73%, 75%, 69%, 70%, and 71% of users mentioned that resources were available, for physical, software, human, organizational, and decision-computerized HIS, respectively. The study showed a strong relationship between computerized information systems with their physical, software, human, and organizational components, and medical and administrative decisions. While the study showed the absence of a relationship between demographic factors and computerized information systems with their hardware, software, human and organizational components, medical and administrative decisions.