We assessed the use of Electronic Health Management Information – eHMIS – and the influence of demographic characteristics on the eHMIS functions. In particular, we explore changes in the usage of eHMIS among health workers. We also determined the effects of demographic characteristics on the usage of eHMIS and assessed any improvement in the ability to use eHMIS after its development. A mixed research design approach was adopted. The respondents were the clinical and non-clinical staff. Data was collected using interviews and questionnaires in three phases: baseline, midline, and final survey. The findings revealed an increase in the frequency of use of the eHMIS for entering and searching data entry from the midline to the final review. Apart from entering data, browsing, and retrieving previously recorded data, other eHMIS functions were not affected by demographic characteristics. On self-efficacy, there was an increase in health workers who felt comfortable using the system in the final survey compared to the baseline survey. In conclusion, enough training, user experience, and support from the management are very important in effective eHMIS implementation.