This dataset contains the experimental data used in the manuscript entitled "Importance of the semimetallic state for the quantum Hall effect in HfTe5". It is composed by longitudinal and Hall resistivity curves as a function of temperature and/or magnetic field at different pressures. It also contains the transition temperatures, activation energies, cross sectional area of the Fermi surface, carriers density and mobility as a function of pressure. Finally, the X-ray diffaction and the lattice parameters are also present in this dataset.