A mathematical model was formulated, coded and validated to predict the evolution of the thermal and microstructural fields in steel probes subjected to the Jominy end-quench test. The heat transfer boundary condition at the probe base was estimated by solving the inverse heat conduction problem (IHCP).The model was validated by comparing the thermal profiles measured in AISI 304 and AISI 4140 steel probes with the values calculated with the model. Once the mathematical model was validated, it was applied to predict, using empirical correlations based on the microstructural profile, the hardness profile along the length of AISI 4140, AISI 1045 and AISI 1080 steel probes. A good approximation was observed between the experimental and calculated hardness profiles.