The aim of this work was to establish the deformation behavior of two vanadium microalloyed medium carbon steels with different contents of carbon and titanium by tensile testing at 77 K. Samples were reheated at 1250 C for 30 min and continuously cooled in still air. Beside acicular ferrite as the dominant morphology in both microstructures, the steel with lower content of carbon and negligible amount of titanium contains considerable fraction of grain boundary ferrite and pearlite. It was found that Ti-free steel exhibits a higher strain hardening rate and significantly lower elongation at 77 K than the fully acicular ferrite steel. The difference in tensile behavior at 77 K of the two steels has been associated with the influence of the pearlite, together with higher dislocation density of acicular ferrite.