In this paper, the problem of adaptive closed-loop parameter estimation and tracking control of a six degree of freedom (6-DOF) nonlinear quadrotor unmanned aerial vehicle (UAV)is studied. To manage the complexity of the problem, the system dynamic is decomposed into two subsystems,i.e. translational dynamics and rotational dynamics. A nested control architecture is adopted to develop both adaptive tracking control and parameter estimation. To stablise the outer loop a virtual control input is proposed using a proportional–derivative (PD) controller to track the x, y and z position. The rotational dynamics of UAV contains unknown inertia parameters appearing in the control structure as well as in a nonlinear dynamic term. An adaptive tracking scheme is designed using the certainty equivalence principle to handle both parameter estimation and tracking control in closed-loop. The idea behind the controller design is to cancel the nonlinear term in the inner loop by estimating the unknown system parameters.The stability of the whole closed loop system is proved with a rigorous analytical study. Moreover, the performance of the proposed controller is verified with several numerical analyses.