In the next generation of wireless communication systems, there will be a need for the rapid deployment of independent mobile users for video and voice communication over wireless network. It can be seen that since the demand for Voice over IP (VoIP) over wireless network is growing, the use of VoIP over mobile ad hoc network (MANET) is expected to grow as well. However, security is a critical issue in MANETs where mobile nodes communicate with each other over relatively unreliable wireless links without any preexisting infrastructure. In this paper, we present a framework for secure voice transmission over multipath MANET. An efficient traffic allocation approach for multipath MANET is proposed in order to deliver real-time traffic over it. The proposed security mechanism was evaluated through two analyses. The correctness of the proposed mechanism was proved using Gong, Needham, and Yahalom (GNY) logic while the security analysis shows that the proposed scheme is resistant to various attacks. For the performance evaluation of the proposed framework, simulations were conducted and the results of the simulation experiments show that it is efficient and robust in terms of various performance metrics.