Percutaneous transluminal laser coronary angioplasty (PTLCA) was undertaken in five patients (four men and one woman, aged 44-72 years) with coronary artery stenosis. The vessel diameter was increased in all patients after PTLCA; complete ablation of the atheromatous plaque succeeded in three. In the other two the catheter could not be advanced across the entire stenotic region. After PTLCA the stenoses were 40-50% of normal lumen. Balloon dilatation was additionally done in all five patients. In three this caused dissection of the vessel wall distal to the stenosis and possible intracoronary thrombus formation: this would suggest that balloon dilatation after laser angioplasty is not recommendable. PTLCA widens the spectrum of invasive methods for treating coronary artery stenosis.