Primary care physicians play a vital role in preventing the progression of diabetic retinopathy (DR) from the initial stages to the late stages. This questionnaire-based analytical cross-sectional study was carried out to assess the knowledge, attitude, practices, and their correlation among 274 randomly selected primary care physicians in Saudi Arabia. Among the studied population, high knowledge, attitudes, and practice scores were observed in 21.5%, 15%, and 29.2% of the physicians, respectively. The mean knowledge score was significantly higher among the age group of less than 30 years (p = 0.031) and the female gender (p = 0.012). The attitude scores were significantly higher among the Saudi physicians (p = 0.027) and those with PHC work experience of less than five years (p < 0.001). Regarding the practices, a significant association was found among the age group of less than 30 years (p = 0.019) and Saudi physicians (p = 0.003). There was a significant positive correlation between knowledge (correlation coefficient (r) = 0.739, p < 0.001) and attitude (r = 0.479, p = 0.007) with the practice scores. It is recommended that targeted continuous medical education, workshops, and seminars are conducted on the prevention and care of DR among primary care physicians. Furthermore, an exploratory multicenter study that involves primary care physicians belonging to all ministries and private sectors is warranted.