This paper focuses on the seismic fragility assessment of typical low-rise and mid-rise reinforced concrete (RC) buildings in Turkey by considering Duzce Damage database, which was compiled after the two devastating earthquakes in 1999 that affected the Marmara region. A set of fragility curves is developed by making use of the building characteristics in the database. The generated fragility curve set is referred as "reference" since it forms the basis of a parametric study. Then the influence of sampling techniques, sample size, type of hysteresis model and limit state definitions on the fragility curves is investigated. The results revealed that the uncertainty in capacity and degradation characteristics have a significant influence whereas the other investigated parameters do not seem to have an important role on the final fragility functions. In the last part of the study, the damage observed in Duzce buildings after 1999 earthquakes is estimated by using the generated fragility curves for low-rise and mid-rise RC frame buildings. Estimated damage distributions seem to be comparable with the actual damage data. (C) 2007 Elsevier Ltd. All rights reserved.