Background A radio diagnostic facility should account for each X-ray film it uses. Through reject repeat analysis it’s easy to manage film use, check on equipment performance, reduce cost of repeated films, measure the efficiency of the radio diagnostic facility, reduce the number of rejected films, and reduce radiation exposure to patients and workers together with improving the quality of radiographs. The aim of the present study was to investigate image quality of plain radiographs in the radio-diagnostic and imaging facility at KCMC hospital. Methodology This was a cross section study performed in the radio diagnostic and imaging department at KCMC hospital using conventional film system during the study period, where by all films which met inclusion criteria were included in the study. Results Reject rate along with its causes was assessed across all plain film (radiograph) examinations in the department. A total of 2445 films were assessed whereby 266 films were rejected. Exposure error constituted 56% of the overall causes of film rejection in the department. Other causes were Fog due to light exposure (9.4%), positioning error (5.3%), processing error (5.3%), double exposure (4.5%), no identification (3.4%), faulty printer (1.5%), artefacts (0.8%), non-exposed films or no image (9.8%) and movement (4.1%).The loss of revenue per month due to 215 rejected/repeated films (radiographs)was approximately 1,112,000/= Tsh. Conclusion The study has shown the high reject rate which exceeded the acceptable range with inappropriate exposure parameters being the foremost cause of rejection. Exposure error and other individual causes of reject have given light into some of the most common problems of quality of radiography service which can be tackled as indicated in the recommendations. These may be useful for improving radiography practice thus patient and personnel dose optimization, effective and sustainable service delivery and good economic management of scarce resources.