In this article we consider the problem of moving in a predefined formation along a reference trajectory in the presence of disturbances in a class of multi-agent systems. The reference trajectory is generated by a neutrally stable exosystem with unknown parameters. The problem is formulated as nonlinear servomechanism problem and an adaptive internal model based controller is used to solve this problem. The performance of the system is verified with simple numerical simulations. © 2010 AACC.