Nano-steels, i.e fully ferritic steels combined with nanometer-sized precipitates, are a new generation of Advanced High Strength Steels (AHSS), extremely suitable for lightweight automotive applications. The ferrite matrix provides ductility and flangebility, whereas the nanometer-sized precipitates significantly increase the strength level. These steels rely on microalloy additions, including Nb, V, Mo and Ti, which form the essential nano-precipitates. An efficient use of these microalloy elements, crucial for commercial implementation, requires further knowledge on the precipitation kinetics of the specific carbides and carbo-nitrides, and a better understanding of the interaction of these nano-precipitates with the austenite to ferrite phase transformation. In this work, the VC-precipitation kinetics of C-Mn-V and C-Mn-V-Mo steels and its interaction with phase transformation is analysed during isothermal holding at different temperatures. Dilatometry experiments are combined with advanced characterisation techniques, such as Small Angle Neutron Scattering (SANS) and Transmission Electron Microscopy (TEM), to disentangle both effects.