This paper addresses the problem of sliding parameter estimation and lateral control of an off-road vehicle-trailer system. The aim is to accurately guide the position of the trailer with respect to a planned trajectory, whatever ground conditions and trajectory shape. Relevant sliding parameter estimation is first proposed, based on the kinematic model of the system extended with side slip angles. Then, a vehicle steering control algorithm is presented to move away the vehicle from the reference trajectory in order for the trailer to achieve accurate path tracking. Reported experiments demonstrate the capabilities of the proposed algorithms.