The optical properties of ordered and disordered FeAl alloy films as well as those of a bulk equiatomic FeAl alloy have been measured in the photon energy range of 0.5-5.0 eV. The influence of the order-disorder structural transition on the optical properties of FeAl compounds has been studied. Experimental results for ordered FeAl are compared with the results of ab initio semi-relativistic extended linear augmented plane-wave calculations, and explained in terms of the electronic energy hand structures.