This paper presents the effect of carriers phase error on MC CDMA performance in downlink mobile communications. Signal to Noise Ratio (SNR) and Bit Error Rate (BER) are analyzed taking into account the effect of carrier phase errors. It is shown that the MC CDMA system is very sensitive to a carrier frequency offset, the system performance rapidly degrades and strongly depends on the number of carriers. For a maximal load, the degradation caused by carrier phase jitter is independent of the number of the carriers. This paper presents the effect of carriers phase error on MC CDMA performance in downlink mobile communications. Signal to Noise Ratio (SNR) and Bit Error Rate (BER) are analyzed taking into account the effect of carrier phase errors. It is shown that the MC CDMA system is very sensitive to a carrier frequency offset, the system performance rapidly degrades and strongly depends on the number of carriers. A maximal load, the degradation caused by carrier phase jitter is independent of the number of the carriers.