In the present study, investigation and comparison laser and tungsten inert gas (TIG) welding techniques for dissimilar butt joint of 304L and 316L stainless steel sheets was carried out. The effects of voltage and laser beam spot size during laser welding and effects of voltage, traveling speed and presence of backing gas during TIG welding on yield strength, elongation, hardness and weld width were investigated. Moreover, in order to examine the mechanical and metallurgical behavior of the weld, microstructure analysis was used. Results showed that welding depth of TIG welding was higher than laser method. It was observed that strength and toughness of samples decreased by increasing voltage in TIG and laser welding. Additionally, by increasing beam spot size in laser welding, strength, toughness and hardness increased. Also, the presence of backing gas during TIG welding resulted in the increase of strength, toughness and hardness of the samples. Display omitted •Enhancement of the strength and toughness because of increase of beam spot size.•Change of temperature gradient resulted in layer microstructure in TIG samples.•TIG samples with backing gas had higher strength and finer isothermal layers.•Massive austenite in laser samples because of massive transformation.