The main purpose of this study was to assess the role of service delivery reform in improvingrnhealth service delivery focusing on Woreda 4 Health Center in KolfeKeranyo Sub-City. To dealrnwith the problems on service delivery, three fundamental research questions were formulated tornevaluate the responsiveness, quality and timeliness of services that provided by the health centerrnas a result of reform implementation in the public health sector as well as challenges encounteredrnin the implementation of reform program in service delivery in woreda 4 health center. Tornconduct the study, mixed method study design was employed, and simple random and purposivernsampling methods were used to select 272 service users and 10 health workers and officials ofrnthe health center and sub-city health office respectively. The main instruments of data collectionrnwere questionnaire, in-depth interview and document analysis. The data were analyzed usingrnfrequency tables and percentage. The finding of the study reveals that the majority of servicernuser participants of the study have confirmed that they were satisfied by the health servicesrnprovided by the woreda health center. This justifies that currently the contribution of thernimplementation of service delivery reform in health service institutions has had significantrnpositive role in improving health service delivery. From the findings of the study it was possiblernto conclude that health service delivery is improving through the implementation of servicerndelivery reform despite some challenges that needed to be addressed in order to achieve all thernintended objectives of the reform program for the benefit of end users in public health servicerndelivery. The need to develop and implement comprehensive grievance and complaints handlingrnmechanisms including a need for sensitization of customers about their rights and privileges, andrnthe need to adopt and implement reward systems are some of the recommendations forward inrnorder to consistently improve better service delivery in all public institutions in general and inrnworeda 4 health center in particular