Objective. To examine the 1-year safety and clinical outcomes associated with the post-marketing early unselected use of sirolimus-eluting stents (SES) in the United States. Background. The safety and effectiveness of SES has been assessed in selected patients enrolled in pivotal randomized trials. This PMS registry was initiated to examine the safety and effectiveness of SES in an unselected population. Methods. Consecutive patients who underwent implantation of >= 1 SES at 38 participating U.S. centers were enrolled in this registry. Results were compared according to "off-" versus "on-label" use of SES. Multivariate regression analyses were carried out in search of predictors of 1-year MACE and stent thrombosis. Results. The mean age of the 2,067 patients (3,367 treated lesions) was 63.7 years. The 12-month follow up was completed by 1,964 patients (95%). SES were implanted for "off-label" indications in 1,173 patients (57%). The 12-month rates of MACE and TLR in that subgroup were 9.2% and 6.2% (p < 0.001 vs. "on-label" indications). Rate of definite/probable stent thrombosis was 1.6% ("off-label") vs. 0.6% ("on-label"), p = 0.026. The rates of MACE, TLR and stent thrombosis in 640 diabetics (31%) were 9.4%, 5.8% and 1.3% (p = 0.021, NS and NS vs. non-diabetics, respectively). Number of lesions, insulin-dependent diabetes and unstable angina were predictors of stein thrombosis. Conclusions. The "off-label" use of SES was associated with higher 1-year cumulative rates of MACE than "on-label" indications, although rates were similar to those seen in historical pre-marketing randomized trials. None of the "off-label" indications were independent predictors of MACE or stent thrombosis.