New Cu x Zn3−x V2O7(OH)2·yH2O (0< x ≤1.5) isostructural to zinc pyrovanadate Zn3V2O7(OH)2·2H2O, were successfully prepared by using a chimie douce technique. The method consists in mixing zinc nitrate and copper nitrate with a boiling solution of vanadium oxide (obtained by reacting V2O5 with few millilitres of 30vol.% H2O2 followed by addition of distilled water). When ammonium hydroxide NH4OH 10% was added (pH≈6), a precipitate was obtained. Using powder X-ray diffraction data, the crystal structures of as-prepared samples were determined by Rietveld refinement. Copper substitutes zinc in the zinc pyrovanadate lattice and is found to introduce distortion in the structure, which is mainly due to the Jahn–Teller effect. Distortion becomes more pronounced when the amount of copper is increased. This restricts the amount of copper which can be incorporated in the hexagonal zinc pyrovanadate lattice.