Conjunctival cultures were obtained from 488 patients undergoing cataract extraction. Bacterial isolation rates from the lids and conjunctiva were 84.6 and 36.7, respectively. Propionibacterium acnes was the only anaerobic organism identified. A significantly lower incidence of P. acnes was observed in the eyes after preoperative conjunctival irrigation using povidone-iodine solution (9%) compared with those using benzetonium chloride solution (30%). Topical use of ofloxacin and cefmenoxime for 1 or 2 days preoperatively, and irrigation of the conjunctival sac with a 16-fold-diluted povidone-iodine solution for at least 30 s immediately prior to cataract surgery are recommended.