A multicentre study of a new preparation of povidone iodine (5% betadine) was carried out on 150 patients undergoing cataract surgery. Pre-operatively the eye was prepared by daubing the peri-ocular skin and a two-minute instillation into the conjunctival fornices. No other antiseptic was applied. Tolerance to the product was evaluated in all the patients: clinical evaluation postoperatively and during a 60-day follow-up period confirmed that the preparation was harmless to the eye. Microbiological investigations (comprising conjunctival swabbing, bacterial culture and count of the bacterial species isolated, before and after application of the product) performed on 60 patients showed a significant fall in the number of colonies after treatment.