Trajectory tracking control of a robotic manipulator demands a well-designed controller that takes into account the nonlinearities, dynamic couplings, uncertainties, and external disturbances exhibited in a robotic system, in order to execute the desired task with the required performance. Sliding mode control (SMC) has been successfully applied to control many systems including robotic manipulators thanks to its inherent property of robustness to uncertainty and insensitivity to disturbances. To achieve such important features, however, SMC design requires precise prior knowledge about system uncertainty and disturbance bounds, which is difficult to determine for a complex system like a high-degree of freedom robotic manipulator. In this thesis, a PID-sliding surface based adaptive robust controller, which combines the good response characteristics of PID with the disturbance insensitivity and robustness of SMC, is proposed for trajectory tracking control of a 5-DOF robotic manipulator. In the first stage of controller design, a PID-sliding surface is considered, so that the system dynamics is rewritten as a function of the sliding manifold and its derivative. And then a control law which consists of a feedforward nominal control, a feedback PID control and a robustifing switching control for the joint input torque is designed. Unlike in conventional SMC, the adaptation laws for the SMC gain and friction coefficients used in the proposed scheme eliminate the need for any conservative off-line estimation about the upper bounds of disturbance and uncertain terms. Furthermore, the stability and finite time convergence of the closed loop system are guaranteed via the Lyapunov method. Finally, the performance of the proposed control scheme is evaluated for joint and task space trajectory tracking using MATLAB/Simulink and the results are compared with other controllers. The simulation results show that for the case of tracking with payload variation, changing operating condition and disturbance, the integral of time multiplied with absolute error (ITAE) in the respective x − y − z axis of the end-effector are 0.459, 0.3083, 0.608 for APDSMC, 0.1195, 0.0317, 0.07483 for ASMC, and 0.0989, 0.02712, 0.03315 under the proposed control scheme. Generally, it was found that the proposed scheme provides a better tracking capability and robustness than APDSMC and ASMC under the undesirable effects of high friction torques, payload variation, external disturbance, and varying operating conditions. Keywords: Five degree of freedom robotic manipulator, Trajectory tracking, PID-sliding surface, Sliding mode control, Adaptive sliding mode control, Friction compensation, Adaptive law, Adaptive sliding mode control with friction compensation.