Abstract Hydrothermal method is a much simpler method of epitaxial multiferroic BiFeO 3 (BFO) film than physical/chemical vapor deposition methods. In this work, epitaxial BFO thin films were fabricated on (0 0 1)-oriented single-crystal SrRuO 3 (SRO)/SrTiO 3 (STO) structures by PVA-assistant hydrothermal method. The results of θ –2 θ scan, ω scan and reciprocal space mappings (RSMs) measured by synchrotron high resolution X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) suggest that the BFO films have relaxed to a single-phase monoclinic structure. The electrical properties observed in BFO (0 0 1) thin films are superior to those of hydrothermal epitaxy reported previously, which indicates PVA plays an important role in fabricating BFO films by using hydrothermal method.