We tried applying a specially-designed cryoprobe to the posterior capsule as well as adding heparin, an anticoagulative, anti-inflammatory compound, to the anterior chamber irrigation solution in an attempt to inhibit secondary cataract formation following a planned extracapsular lens extraction in 36 rabbits. The first group received both cryo treatment and heparin; a second group received heparin without cryo treatment; a third group received neither heparin nor cryo treatment. Complete opacification of the lens developed 3 months after the operation in all the rabbits not treated with heparin, and in 50% of those that received heparin. The addition of cryo treatment to the heparin-treated rabbits further reduced opacification by 20%. We conclude that in rabbits, cryo treatment, combined with intracameral administration of heparin during surgery, has a significant inhibitory effect on secondary cataract formation.