While much recent research focuses only on providing routing services for ad hoc networks, very little work has been done towards achieving anonymity for wireless ad hoc and sensor networks. However, malicious nodes in a wireless and mobile ad hoc environment can jeopardize the security of the network if the issues of secure data exchange are not properly handled. Encryption cannot fully protect the data communicated between nodes, as routing information may expose the identities of the communicating nodes and put their relationships at risk. In this paper, we propose an efficient anonymous routing protocol that uses a mobile agent paradigm for wireless and mobile ad hoc networks. In our protocol, only trustworthy nodes are allowed to participate in communications and the misbehavior of malicious nodes is thus prevented effectively. We describe our protocol and provide its performance evaluation based on simulation experiments implemented in an ns-2 simulator. Compared to the SDAR protocol, our experimental results demonstrate that our scheme not only achieves the necessary anonymity in mobile ad hoc networks, but also provides more security with reasonably little additional overhead.