The influence of metal coatings of glass substrates on the laser crystallization process of amorphous silicon is investigated. Three different metals were chosen: Mo, Al and Ni. Amorphous silicon was deposited on top of the metal and crystallized using a XeCl excimer laser. Auger electron spectroscopy and Raman measurements show that in case of Ni and Al an intermixing with the polycrystalline silicon (poly-Si) due to the laser treatment occurs resulting in a rough film. In the case of Al, regions of highly Al doped poly-Si were observed. On the other hand laser crystallization of a-Si:H on Mo coated glass does not result in an intermixing. The average grain size varies with the laser fluence. In the super lateral growth regime grains of size up to 1 mum can be fabricated. These large grains show a preferential surface orientation along the {1 1 1} direction.