In this paper, an effective operational method will beused to determine the numerical solution of a specific Nonlinear Fractional Volterra-Fredholm integro-differential (NFVFID) equation. The method is based on CAS wavelets and Block Pulse Functions (BPFs) and their operational matrices. The main characteristic of this approach is to reduce a NFVFID equation to asystem of algebraic equations, which greatly simplifies the problem. Also some numerical examples are provided to illustratethe accuracy and computational efficiency of the method.