Background: In cataract surgery, viscoelastic agents form anterior chamber, complicating to posterior capsular opacity and pigment deposition over intraocular lens after lens implantation. We compared the rate of these complications for air bubble and viscoelastic agents. Methods: Patients with senile cataract and candidate for routine cataract extraction were studied. They were randomly divided into group A (n=62) and group B (n=66). During operation and at the time of intraocular lens implantation, anterior chamber was formed by air bubble (in group A) and with viscoelastic agents (in group B). All patients were followed for 3 to 6 months. Results: The rate of posterior capsular opacity and pigment deposition over the intraocular lens were significantly higher in group B (40.9% vs. 21%) than group A (30.3% vs. 9.7%), respectively. Conclusion: Air bubble is a good substitution for viscoelastic agents in the formation of anterior chamber during cataract, either for decreasing complications or expensive materials. Keywords: Posterior capsular opacity, cataract extraction, viscoelastic agent, air bubble