This thesis investigates the performance of the Optimized Link State Routing (OLSR) protocol on Voice over Internet Protocol (VoIP) applications in Mobile Ad hoc Networks (MANETs). Representative VoIP traffic is submitted to a MANET and end-to-end delay and packet loss are observed. Node density, number of data streams and mobility are varied creating a full-factorial experimental design with 18 distinct scenarios. The MANET is simulated in OPNET and VoIP traffic is introduced using one source node to send traffic to random destinations throughout the network. Simulation results indicate delay is between 0.069 ms to 0.717 ms, which is significantly lower than the recommended 150 ms threshold for VoIP applications. Packet loss is between 0.32% and 9.97%, which is less than the 10% allowable packet loss for acceptable VoIP quality. Thus OLSR is a suitable routing protocol for MANETs running VoIP applications.