The relationship between image quality and processing conditions was assessed in a survey of 26 primary health care clinics in Riyadh City. Each clinic is equipped with a basic X-ray room and a darkroom that has a small table-top automatic processor. Rooms were evaluated for the quality of safe light, light leakage, storage of films and chemicals and processor temperature setting. A relationship was obtained between the quality of these parameters and the analysis of characteristic curves (H and D curves) of images produced at each facility. Base plus fog indexes in 50% of clinics were found to be above normal values. Contrast and speed indexes were above control in 46 and 19% of clinics, respectively. The results showed that the image quality is negatively affected when the above conditions are unsatisfactory, even though the X-ray machine, cassettes and films used are in good condition. In conclusion, image quality can be improved significantly by applying quality control principles related to darkroom conditions.