Most frequency hopping (FH) systems use non-coherent reception due to the difficulty of synchronization of the carrier phase. This implies a performance loss in these systems. Multicarrier frequency hopping systems make coherent reception feasible. The performance of these systems in presence of jamming is seldom investigated. In this paper, the performance of coherent multicarrier frequency hopping binary PSK (MC-FH/BPSK) system under the effect of jamming is studied. The considered types of jamming are partial band jamming and broadband jamming. It is shown that a smart jammer should be present in all subbands. The error performance of the MC-FH/BPSK system is compared with that one of the single carrier FH/BPSK system in presence of jamming. Computer simulations are provided to validate the theoretical developments.