The public sector plays an important part in development of the nation as it fosters a socio-economic and political climate supportive to the growth of the nation. The success or failure of an organization can be link to its staff, which is considered critical to the delivery of services that aim to meet the required standards. This study aimed to evaluate the impact of staff training program on the effective service delivery in the government sector of Sri Lanka. The specific objectives were; To determine the nature of staff training program conducting for government officers in Sri Lanka, evaluate the factors affected to increase or decrease standards staff training program, examine the opinion of employees at each level in the public sector regarding staff training programs and find out possible solution and recommendation for future studies. The study assumed qualitative research design. Research sample was 20 public sector employees and the data in this study was collected using in-depth interviews. The study established that the impact of training programs on the effective service delivery is unsatisfactory. This is due to a variety of problems, such as the fact that the content of the programs is not planned based on the mission of the organization, there is no unique method to achieve the goals of the organization and transform the performance, carelessness in selecting resource persons, lack of equal opportunity to all staff to undertake training, and trainings are rare. Finally the study establishes that these challenges hindering achievement of quality service.