The purpose of the study is to evaluate the influence of professional ethics on staff performance in public sector in Uganda with focus o ministry of public service in Uganda. The objective included to examine the role of professional ethics in promoting staff performance in ministry of public service in Uganda, to establish the challenges faced by the organizations in instilling professional ethics in employees in Uganda and to establish the way forward that the ministry of public service can put in place to ensure that professional ethics are adopted by employees in Uganda. The study used descriptive design, the design was selected because the researcher intend to establish facts that already. The study was collected from the ministry in the 60 employees of the ministry. The data was collected using the questionnaires that were self administered The study findings on the first research objective concluded that professional ethics help in promoting staff performance in mthe inistry of public service in Uganda. On the second research objectives ,the study concluded that there are challenges faced by the organizations in instilling the professional ethics in the ministry. The third objective concluded that the ministry of public service has measures to ensure that professional ethics that should be adopted by employees in Uganda but these need to be strengthened to improve the ethics of professional nature in the organization The study findings reveal that professional ethics promotes staff performance. The study on the first objective recommends that there is need for improving the state of the professional development among the employees through ethe stablishment of ethics committees, ethical manuals and training on ethical strands in the ministry as means for providing an improved behavior for the organization staff. On the second objective, regarding the challenges in instilling professional ethics through improving the state of the work environment necessary for improving the system functionality hence enhancing the prevalence of professional and ethical environment that can transform the mechanisms for dthe evelopment of ethical values for the organization. The third objective, the study recommends for the improvement of the state of affairs requires employing improving the state of the ethical climate, developing a human resource-effective and implementable disciplinary manual intended to design, facilitate and provide the mode of work necessary for the development of employees competency in the organization.