The response of plain carbon Ck-45 steel to laser trnnsfol111ation hardening is invest igated, and the influence of process conditions such as beam power and size, traverse speed and initial surface condition is examined. Results for Ck-45 and Ck-60 steels arc compared, in an effort to determine the effect of carbon content. Ck-60 steel presented higher case depths than Ck-45, due to the diffcrcnces in the critical austenitization lemperatures between the two steels" Regarding the achieved hardncss, the two steels prcsented smaller differences than those-expccted by their difference in carbon content.