The aim of this study was to identify the appropriate parameters for laser welding of steel plates. The mechanical characteristics and metallurgical microstructures of the joints were analysed experimentally. Welded joints were made using two different types of steel (Cr-Mo low alloy steel and austenitic stainless steel). Samples were cut from welds and examined macrographically; tensile and microhardness tests were also performed. Observations of these samples showed the beneficial effects of narrower molten and heat affected zones and the consequent advantageous reductions in distortions and residual stresses. On the basis of these experimental results we conclude that both ferritic and austenitic steels can be properly welded, with good mechanical and metallurgical results, using consumable inserts pre-fitted to the edges before welding, provided that suitable welding parameters are chosen.