Complications of cataract and intraocular lens surgery fall into two groups, sporadic and recurring. Sporadic complications include endophthalmitis and there is evidence that an intact posterior capsule inhibits the inoculant from reaching the vitreous. An acute intraoperative suprachoroidal hematoma occurs in 0.9% of cases, but if this is recognized the visual outcome results are excellent. Recurring problems include astigmatism which is related to the type of incision and the placement of sutures. New incisions reduce astigmatism and the need for sutures. Vitreous loss can be limited in phacoemulsification and vitrectomy should be performed using a bimanual technique. No reliable way to treat aphakic cystoid macular edema yet exists. Postoperative glaucoma and posterior capsule opacification remain a problem. The use of capsulorhexis can lead to pseudomyopia or pseudohyperopia.