This study tests whether stent implantation without anticoagulation after catheter recanalization of coronary occlusions can improve outcome compared with balloon angioplasty alone. One hundred ten patients were randomly assigned to angioplasty alone (no stent group) or stent implantation (stent group) after successful recanalization and balloon angioplasty. The type of stent and angioplasty technique utilized were decided by the operator. The acute procedural success in both groups was 100%. The acute minimal lumen diameter (MLD) was 1.85 +/- 0.44 mm in the no stent group versus 2.54 +/- 0.53 mm in the stent group (p <0.01). The diameter stenosis was 21 +/- 13% versus 3 +/- 14% (p <0.01). This was achieved not only by the stent implantation itself but primarily by a larger maximum balloon diameter in the stent group after stent implantation (3.32 +/- 0.55 mm vs 2.86 +/- 0.4 mm, p <0.05). After 4 months, the MLD was 1.15 +/- 0.73 mm in the no stent group versus 1.81 +/- 0.9 mm in the stent group (p <0.01). The diameter stenosis was 56 +/- 29% versus 34 +/- 28% (p <0.01). After 2 years, event-free survival was 26% in the no stent group and 52% in the stent group (p <0.05). Thus, acute and long-term procedural and angiographic success of stent implantation without anticoagulation after recanalization of total coronary occlusions is superior to that of balloon angioplasty alone. This beneficial effect is mainly the result of the larger balloon diameters, which may be used after stent implantation.