In 3G cellular systems, WCDMA air interface will be used. A transmission bandwidth of 5 MHz will enable the use of Rake receivers, which can capture more multipath energy. This work investigates the effect of number of Rake fingers and relative power levels of multipath components on system performance. Data from radio channel propagation measurements in UMTS bands in Manchester city center were used to obtain multipath statistics. Four channel profiles were selected to be used in simulations for perfomance analysis of a 3G system that employed a Rake receiver with 1-5 fingers. The simulations were performed for spreading factors of 16, 32 and 64. Results showed that the optimal number for fingers depends on channel profile.