A routing algorithm for two-hop CDMA cellular systems in combination with call admission control is proposed with the aim of capacity enhancement under heavy traffic load condition. Multihop transmissions are mainly applied to decrease the transmit power of each station and extend the cell coverage area for cellular systems. Here, in this paper, its potential benefit is studied that the multihop routing and spatial frequency reuse might increase the network capacity. A condition for interference reduction by changing some single-hop connections to two-hop connections is analyzed and an efficient routing scheme for two-hop CDMA cellular systems to reduce co-channel interference at the base station is proposed. Simulation results indicate that by using proposed routing algorithm in combination with call admission control, the network capacity is increased.