In the area of laser welding, numerous studies have been performed the past decades using either analytical or numerical approaches, or both combined. However, most of previous studies were process oriented and modeled differently in conduction and keyhole welding. In this research, the results of calculation using various heat source equations that have been proposed in previous studies were compared to the predictions of a new model. This model treats the problem of predicting, by numerical means, the thermo-mechanical behavior of laser spot welding for thin stainless steel plates. A finite element code, ABAQUS, is used for the heat-transfer analysis with a 3D model. Experimental studies of the laser spot welding have also been conducted to validate the numerical models presented. The results suggest that the predicted temperature profiles and weld dimensions vary according to the heat source equation of the laser beam. For this reason, it is essential to incorporate an accurate description of the heat source. Thermal and mechanical analyses of the laser micro-welding of a small structure are performed from these results. (C) 2002 Elsevier Science B.V. All rights reserved.