In this study, carbon-doped tungsten powder was processed by laser powder bed fusion (LPBF) and characterized for defects by optical microscope (OM) and scanning electron microscope (SEM) of metallographic cross sections, for microstructure by electron backscatter diffraction (EBSD) imaging, and for mechanical properties by three-point bending test at room temperature and 300°C. The optimization of the LPBF process involved process parameters in the transition of the melt pool cross sections from the light conduction mode regime to the light keyhole mode regime utilizing the dimensionless enthalpy. Compared to pure tungsten, the microstructure was refined and the epitaxial growth of grains was reduced. It was possible to reduce the amount of intergranular cracking and obtain samples without cracks in the inner regions, but surface cracks remained. By alloying with low amounts of carbon, the relative density increased to 99.9% with higher porosity at the surface areas where the cracks are located. This study is an important step toward the production of defect-free tungsten components with mechanical properties that meet market requirements using LPBF.