In this paper, we study the parallel interference cancellation receiver (PIC) efficiency, in direct sequence optical code division multiple access system (DS-OCDMA) with prime codes (PC). We develop the analytical expression of the error probability in the chip synchronous case, for PC. We show that the PIC receiver permits to suppress totally the effect of multiple access interference (MAI) for prime code, and leads to an error free O-CDMA link in the noiseless case, for whichever PC employed. Simulation results have validated the theoretical analysis. Finally, we show that the PIC receiver permits to reduce the required code length for a given bit error rate