Recent developments in additive manufacturing technologies allows generating different type of microstructure by modifying the additive manufacturing parameters. Indeed, with the laser powder bed fusion process, the laser power, energy density or laser scan strategies are such of parameters which affect size, morphology and orientations of grains. This allows to build microstructures which were no accessible with conventional processes. Furthermore, the control of laser scan strategies allows to significantly reducing the size and density of defects inherent to the process (gas pores, lack of fusion). These advances make it possible to study the role of microstructure and defect on fatigue crack initiation behaviour for additive manufactured materials. This paper aims to take this opportunity for studying the 316L stainless steel built with the laser powder bed fusion process.