This research was aimed at finding out the perception and awareness of service providers and clients toward financial sustainability of the National Health Insurance Scheme in the Edo South Senatorial District of Edo state. A descriptive study was adopted in this research and the study populations were clients and service providers accessing NHIS services in NHIS clinics within Oredo, Orhionmwon and Ikpoba-okha Local Government Area, whom were selected using a judgmental non-probability sampling method. The results from this study showed significant statistical difference (p<0.05) in responses to NHIS reduction of healthcare financing burden as most of the respondents strongly agreed that NHIS reduces healthcare financing burden. There was also significant statistical difference (p<0.05) in perception of clients and service providers on the NHIS efficiency in providing healthcare services as most of the respondent strongly agreed that NHIS is efficient in providing healthcare services. Results also showed significant statistical difference (p<0.05) in level of satisfaction by clients and service providers as most of the respondents were very satisfied with NHIS services.  There was significant statistical difference (p<0.05) in response of respondents to preference of NHIS over the cash for service system in which most respondents prefers NHIS over cash for service system. There was significant statistical difference (p<0.05) in perception of clients and service providers on the financial sustainability of NHIS as most of the respondent strongly agreed that NHIS is financially sustainable. The result also shows that a significant number of respondents are unsatisfied with the NHIS services despite that they still want the scheme to be sustained.  One of the recommendations made is that Registration should be made compulsory so as to ensure sufficient pooling of resource, spreading of risk and minimization of cost. This should solve the problem of drug insufficiency and availability.