Seismic risk assessment of two real RC multi-story buildings, located on similar soil profile in Kocaeli, is conducted in respect to code-based linear and nonlinear approaches, as well as to P25-v2 Method, a recently suggested method for risk evaluation and preliminary assessment of existing buildings against life-loss. Twenty-five different parameters and seven different collapse criteria are taken into consideration in the suggested P25-v2 Method, including soil and topographic conditions, earthquake demand, various structural irregularities, material and geometrical properties, and location of the buildings. After summarizing the different methodologies and describing the case study buildings, 3D linear-elastic and static nonlinear analyses are performed in parallel to the application of the P25 Method-v2. One of the two case study buildings totally collapsed during 1999 Kocaeli Earthquake, while the other survived with negligible damage, noting that both had legal construction and occupation permissions. SAP2000 and SeismoStruct software packages have been utilised for the analysis procedure to find out the damage states of the structural members at critical stories and to determine the performance levels of the case study buildings. The code-based performance levels and the final performance scores obtained by the preliminary assessment technique are compared in order to underline the existence of the correlation between the detailed procedure and the suggested preliminary assessment technique with the real damage state. Consequently, structural inadequacies, weak points of the buildings and failure reasons are also discussed in this paper.