Since the first research works in the end of 1980s on the semi-solid forming of steel, this process has presented a great interest and a real industrial potential. Several research teams, all over the world, have shown the feasibility of such a process. Working on the parameters which have an influence on the process, they pointed out the "technical locks" which must be overcome to allow industrialization of the process. A first and perhaps most important difficulty is the reliability of the forming tools in an industrial production context. Much work has therefore been devoted to identify ways to increase tools life. A second important point is the possibility to obtain sound microstructure and satisfactory mechanical properties. This paper is a state of the art review on the subject of the thixoforming of steel, restricted to forming of semi-solid reheated steel. Semi-solid forming process carried out after partial solidification are therefore not covered. The reader interested in such processes may refer to the review recently published by Hirt et al. . The present review considers, in turn, the different steps of an hypothetical production line and their particular challenges, from the raw material to the final product.