In this study, Telfer's GEOSIM method for the computation of ship resistance at full scale has been applied by CFD (Computational Fluid Dynamics) approach. For this purpose, the KCS (KRISO Container Ship) hull has been investigated numerically with k-e turbulence model for three different scales and full scale analyses by URANS (Unsteady Reynolds Averaged Navier-Stokes) method. Full scale ship resistance has been predicted using the numerical results computed at different model scales by Telfer's GEOSIM method. The numerical results at three scales have also been extrapolated separately to that at full scale by ITTC 1978 performance prediction method. An experimental study has also been carried out at a model scale for validation. The results by Telfer's GEOSIM method have been calculated almost in full compliance with those of CFD approach. While the difference between the results of CFD and those of ITTC extrapolation method is about 5% at full scale, the difference between the results of CFD and those of Telfer's GEOSIM method has been found to be less than 1% at full scale. In addition, this method has been applied to estimate the nominal wake coefficient at full scale from model scales. A very good correlation has also been found for nominal wake coefficient.