Background: Despite the advances in the interventions, long-term outcome is still limited by restenosis. Angiographic restenosis has been reported in 50% of patients within 6 months after balloon angioplasty. Although stent implantation has been shown to reduce restenosis as compared with PTCA, in-stent restenosis (ISR) still occurs in 10-30% of the patients. Drug-eluting stents containing the immunosuppressive agent (Rapamycin) and the anti-mitotic agent (Paclitaxel) have shown encouraging reductions in restenosis in de novo lesions, and possibly in ISR lesions. Methods: This observational study was conducted in the Cardiology Department at the Essen University Hospital, Germany. A total 106 consecutive patients received either Cypher stents (n=54) or Paclitaxel stents (n=52) to treat either de novo lesions (Cypher, n=40 vs. Paclitaxel, n=30) or restenotic lesions (Cypher, n=14 vs. Paclitaxel, n=22) and underwent angiographic follow-up between Aug 2002 and Feb 2004. The stents were chosen to achieve a stent-to-artery ratio of approximately 1.1:1.0. All the patients received 100 mg Aspirin indefinitely and 300 mg Clopidogrel as loading dose before the intervention and 75 mg for 6 months after the intervention. The primary endpoint was DS% at follow-up. The secondary angiographic endpoints included late loss, binary restenosis, and minimal lumen diameter at follow-up. The clinical secondary endpoints included the incidence of death, the need for bypass surgery or intervention to treat resteonsis of the target lesions, myocardial infarction (Q-wave or non-Q-wave), TVR, and TLR. Results: The Diameter stenosis (DS %) at follow-up was (Cypher, 25.11± 18.24 % vs. Paclitaxel 25.90 ± 21.23 %; P=0.83). Minimal lumen diameter at follow-up was (Cypher, 2.27± 0.62 mm vs. Paclitaxel, 2.34 ± 0.72 mm; P=0.57). Binary restenosis was detected in 7 patients (12.9%) of the Cypher group compared with 8 patients (15.3%) of the Paclitaxel group (P=0.65). Late loss was similar between the two groups. No patients in the both groups suffered from MI either Q-wave or non-Q-wave during follow-up duration. The incidence of death was 0% in the both groups. Coronary bypass surgery was not performed to any patient in the both group. TLR and TVR were similar between the tow groups. Conclusion: In this observational study we did not observe significant differences between the sirolimus-coated Cypher stent and non-polymer paclitaxel-coated Cook stent in terms of angiographic follow-up parameters as well as clinical events.