The rise in the use of additive manufacturing highlights the importance of knowing the properties of the materials employed in this technology. Therefore, for the commercialization of thermal applications with this technology, heat management is essential. Here, computational modelling is often utilised to simulate heat transfer in various components, and knowing precisely the values of thermal conductivity is one of the key parameters. In this line of research, this paper includes the experimental study of three different types of resin used in additive manufacturing by stereolithography. Based on a test bench designed by researchers from the Public University of Navarre, which measures thermal contact resistances and thermal conductivities, the thermal conductivity analysis of three kinds of resin is carried out. This measuring machine employs the temperature difference between the faces and the heat flux that crosses the studied sample to determine the mentioned parameters. The thermal conductivity results are successful considering the constitution of the material studied and are consistent with the conductivity values for thermal insulating materials. The ELEGOO standard resin stands out among the others due to its low thermal conductivity of 0.366 W/m K. Article Highlights Calculating thermal conductivity of three resins used in additive manufacturing by stereolithography. Contributing to a knowledge-based design of heat sink in thermal conductivity measurement bench. Improvement of the thermal conductivity measurement bench by reducing the uncertainty for its application in low thermal conductivity materials testing. Graphical abstract