Purpose : We evaluated the efficacy of the PCR which is known as more sensitive method than culture in the diagnosis of causal microorganisms of the infective endophthalmitis. Methods : We used 0.3 ml of aqueous humor and 0.5 ml of vitreous sample in 3 cases of postoperative and 1 case of endogenous endophthalmitis for detecting causal microorganisms. To detect the bacteria we used universal, Gram positive and negative primers, and to detect the fungus we used fungal primer. Results : Three cases of endophthalmitis, there was no bacteria in the bacterial culture for 10 days but PCR results identified causal microorganisms in all cases. Conclusions : PCR is effective in the fast and accurate diagnosis of infective endophthalmitis and especially in the culture-negative endophthalmitis.