Purpose The purpose of this paper is to investigate effects of layer thickness on densification, surface morphology, microstructure and mechanical and corrosion properties of 420 stainless steel fabricated by laser-powder bed fusion (L-PBF). Design/methodology/approach Standard specimens were printed at layer thickness of 10, 20 and 30 mu m to characterize Archimedes density, surface roughness, tensile strength, elongation, hardness, microstructural phases and corrosion performance in the as-printed and heat-treated condition. Findings Archimedes density slightly increased from 7.67 +/- 0.02 to 7.70 +/- 0.02g/cm(3)and notably decreased to 7.35 +/- 0.05 g/cm(3)as the layer thickness was changed from 20 mu m to 10 and 30 mu m, respectively. The sensitivity to layer thickness variation was also evident in properties, the ultimate tensile strength of as-printed parts increased from 1050 +/- 25 MPa to 1130 +/- 35 MPa and decreased to 760 +/- 35 MPa, elongation increased from 2.5 +/- 0.2% to 2.8 +/- 0.3% and decreased to 1.5 +/- 0.2, and hardness increased from 55 +/- 1 HRC to 57 +/- 1 HRC and decreased to 51 +/- 1 HRC, respectively. Following heat treatment, the ultimate tensile strength and elongation improved but the general trends of effects of layer thickness remained the same. Practical implications Properties obtained by L-PBF are superior to reported properties of 420 stainless steel fabricated by metal injection molding and comparable to wrought properties. Originality/value This study successfully the sensitivity of mechanical and corrosion properties of the as-printed and heat-treated parts to not only physical density but also microstructure (martensite content and tempering), as a result of changing the layer thickness. This manuscript also demonstrates porosity evolution as a combination of reduced energy flux and lower packing density for parts processed at an increasing layer thickness.