Let q be a prime power and F q be a finite field. In this paper, we study constacyclic codes over the ring F q + uF q + vF q + uvF q , where u 2 = u, v 2 = v and uv = vu. We characterize the generator polynomials of constacyclic codes and their duals using some decomposition of this ring. Finally we study the images of self-dual cyclic codes over F 2 m + uF 2 m + vF 2 m + uvF 2 m through a linear Gray map.