Crystals of the spin dimer system Ba3Cr2O8 have been grown for the first time by the traveling solvent floating zone method. Obtained crystals were characterized by X-ray diffraction (XRD) at room temperature and refined in the space group R (3) over barm. The magnetic susceptibility shows a broad maximum around 16 K and below this drops off sharply, providing evidence for the spin gap which was estimated to be 15.6(3)K. From the susceptibility and single crystal XRD measurements, it has been confirmed that the Cr ions are found in the rare +5 oxidation state in this material. (C) 2008 Elsevier B.V. All rights reserved.