In this paper, the performance of multicarrier (MC), multicode (MCD), code division multiple access (CDMA) system employing wavelet packets (WPs) for modulation in the presence of narrowband jamming is investigated. The system's performance is evaluated by means of bit error rate (BER) and outage probability (Pout). The effects of channel intensity profile, type of wavelet families and their filters length, number of superstreams of wavelets and number of substreams on the system performances were investigated by means of analytical methods and numerical results. Also, the performance of the system is compared to that of MC/MCD-CDMA based on sinusoidal carrier. Results reveal considerable performance improvement of MC/MCD-CDMA system based on WPs carrier over the system based on sinusoidal carrier.