Abstract: In this paper an RLS-based adaptive controller for active noise and vibration control systems is presented. This adaptive controller is designed based on feed-forward architecture and uses IIR filter as the control filter. Because the derived algorithm for ANVC systems is based on RLS recursion, its computational complexity is of order ) ( 2 n O which is too high for real-time implementations. Besides, it is also vulnerable to round-off and finite precision errors that may occur in real-time implementation of the algorithm. Since the aim is to test the algorithm in an experimental duct a fast array implementation of the algorithm is proposed. This fast array form is used the extended the fast array algorithms for FIR filter which is studied in literature before. The proposed fast array solution of the algorithm not only reduces the computational complexity to the order of ) (n O with the same performance, but also because of its matrix nature it has good numerical stability in real-time applications which is a necessity in active noise and vibration control applications.