Out of a total of 1,500 percutaneous coronary angioplasties (PTCA), 55 (3.6%) were associated with balloon rupture. Lesion calcification was noticed in 7 of these 55 patients (12.7%). Balloon rupture occurred at a mean pressure of 10.7 atmospheres. All balloons were retrieved without difficulty. Intimal tears were noted in 18 (32.7%) cases. Three patients required bypass surgery. In 29 patients restudied angiographically, the restenosis rate was 38%. Balloon rupture during PTCA does not seem to be associated with detrimental consequences.