An easy, quick and low cost hydrothermal synthesis was developed to prepare high surface area phospho-olivine LiFePO4 powders to be used as cathode material for Li-ion batteries. The samples were prepared in double distilled water starting from commercial LiOH, FeSO4, H3PO4 and using solutions with different concentrations of a surfactant compound (CTAB), in order to increase the specific surface areas, obtaining powders with very small grain size. The structural, morphological and electrochemical properties were investigated by means of X-ray powder diffraction (XRPD), ICP-AES, BET method, scanning electron microscopy (SEM) and constant current charge–discharge cycling. The electrochemical performances of LiFePO4 prepared in this manner showed to be positively affected by the presence of CTAB during synthesis, showing capacities near the theoretical value, only slightly affected by the discharge regime (from C/20 to 10C).