Preoperative eyes which had been treated with gentamicin for one-half day were subjected to one of two povidone-iodine (PI) preparations. The control eye was prepared using a previously described 5% PI one-drop technique, while the paired eye was irrigated with a 0.02% PI solution. Aerobic and anaerobic bacterial cultures were taken of each eye before and after PI applications. Statistical analysis of the data indicates that both techniques were equally effective in reducing surface colonization of the anaerobic cocci and bacilli, the viridans streptococci and micrococci. Both methods were also equally ineffective in reducing the numbers of coagulase-negative staphylococci from the surface of the eye. With the apparent emergence of gentamicin-resistant coagulase-negative staphylococci the potential for staphylococcal endophthalmitis is increasing.