This paper discusses the application of time-delay control law for robust trajectory tracking control of underwater vehicles. The idea is based on the cancellation of uncertain dynamics in the plant by estimating a function which closely approximates the plant uncertainty at any given instant. This is done through the feedback of the derivative of the state and the previous control inputs. By deriving the controller in discretetime the necessity of using state derivative is removed. The controller is computationally simple and easy to implement. The effectiveness of the proposed controller is demonstrated through simulations for various test conditions. © 2006 IEEE.