Abstract It has been recognized in automotive sector that the use of hot stamped parts for the automobile body-in-white allows significant weight saving and reduction of CO2 emissions. The weight reduction is accompanied by high stiffness and increased crashworthiness, which improve the passengers’ safety and allow the development of more complex vehicle’s design. In direct hot stamping, the 22MnB5 sheets are heated above the austenitization temperature, and then, formed and quenched in cooled dies by using a minimum cooling rate of 27°C/s in order to obtain the direct martensitic transformation from the initial austenite. To evaluate part feasibility, minimize production cost and improve process robustness in hot stamping, numerical simulations are becoming increasingly important, where data regarding the formability of the material at high temperature plays a central role in the simulation. A survey of the literature shows that the complex aspects of the process have been extensively investigated from an experimental point of view, but limited studies concerning the numerical modeling of the process can be found. The aim of the present paper is to explore the critical aspects of the numerical modeling in terms of material formability in hot stamping. Numerical simulations of hot Nakajima tests at the critical temperature of 600°C were performed by using explicit numerical method, while experimental tests are carried out in the same condition. The comparison of the numerical results and the experimental data demonstrates the influence that the thermal cycle applied during the experimental tests may have, since it governs the phase transformations that affect the material formability.