Intraocular lens (IOL) decentration was studied in a series of 569 consecutive eyes that had extracapsular cataract extraction (ECCE) and posterior chamber IOL implantation. In 383 of the eyes, an envelope capsulotomy (EC) was performed; in 186, a continuous curvilinear capsulotomy (CCC). In 33 eyes, the anterior capsule had one radial tear that reached the lens equator. In all eyes, IOL decentration was determined more than six months after surgery. Mean IOL decentration was 0.42 +/- 0.02 mm in the EC eyes and 0.27 +/- 0.01 mm in the CCC eyes (P < .001). In the CCC eyes, mean IOL decentration was 0.23 +/- 0.02 mm when the anterior capsule had no tears and 0.42 +/- 0.06 mm when it had one radial tear (P < .01). In the EC eyes, mean decentration was less with lenses with a total diameter of 11.0 mm or less and 360 degree circular loops (compressible disc and circular open-loop lenses) than with C- and J-loop lenses with a total length of 13.5 mm to 14.0 mm. With the C- and J-loop lenses in all three capsulotomy groups, mean decentration was related to the presence and number of tears in the anterior capsule: 0.58 mm in the EC eyes, 0.41 mm in the CCC with tear eyes, and 0.23 mm in the CCC without tear eyes. A similar relationship was seen with the bag-implanted lenses: 0.48 mm in the EC eyes, 0.28 mm in the CCC with tear eyes; 0.22 mm in the CCC without tear eyes.