Cementation is a heat treatment used to add carbon to the surface of a piece of steel (steel that must have a percentage of carbon less than 0.25%) in order to obtain a surface with high hardness and a sufficiently tenacious core or centre. One of the methods used to achieve the characteristics mentioned above is solid cementation, a treatment carried out using charcoal or coke as substances that add carbon to the surface of the part. In this work, a SAE 1020 steel (discs 76.2 mm in diameter and 10 mm thick) is heat treated with solid cementation using rice husk as a carbon-contributing substance. The thermal treatment was carried out at a temperature of 950°C with a holding time of 7 hours. The rice husk was used in two conditions: alone and in mixture with calcium carbonate. It was made at the same time cementation with charcoal, under the same conditions given to the treatment with rice husk. This substance was used to establish a comparison in the results and to evaluate the cementitious effect of the rice hull. It is evident in the results that effectively the rice hull adds carbon to the surface of the piece of steel, however, this capacity of contribution is low compared to that of charcoal. In general, it is observed in the microstructural analysis and in the surface hardness obtained that charcoal unlike rice hulls provides better characteristics in terms of carbon penetration thickness and the achievement of greater hardness.