Two hundred consecutive patients were enrolled in a randomized, prospective clinical trial evaluating the efficacy of diclofenac sodium (Voltaren Ophthalmic) in reducing patient discomfort after cataract surgery. Other factors evaluated were the effect of preoperative flurbiprofen (Ocufen) in preventing intraoperative miosis and on postoperative discomfort and the effect of incision size and intraocular carbachol (Miostat) on postoperative comfort. Diclofenac significantly reduced discomfort during the first 24 hours after surgery but not two to three days postoperatively, although there was a trend toward reduction. Flurbiprofen given preoperatively did not affect postoperative discomfort. It also did not affect pupil size at the start of surgery but did reduce intraoperative miosis. Incision size (5.2 mm versus 7.0 mm) had no effect on discomfort. Miostat did not affect discomfort, although there was a trend toward more discomfort. The results indicate that topical diclofenac, given immediately after cataract surgery, significantly reduces discomfort during the first 24 postoperative hours.