Differential thermal and thermogravimetric analysis investigations of VO(PO3)(2) at elevated temperatures shows that the substance melts at 1035degreesC incongruently with decomposition in two condensed phases and evolution of gaseous oxygen. In order to grow single crystals at lower temperature two techniques were used: flux and chemical vapor growth. alpha- and beta-VO(PO3)(2) single crystals were grown from V-P-O flux and by vapor transport mediated by TeCl4. Because of a high viscosity of the flux the crystallized material contains inclusions of flux. Vapor transport growth leads to crystals of a higher quality. The crystals contain no inclusions of foreign phases and contaminations of Te and Cl which might be introduced by transport agent. Magnetic susceptibility measurements of beta-VO(PO3)(2) single crystals indicate a quasi one-dimensional system with weak antiferromagnetic interactions. The temperature dependence of the magnetic susceptibility shows the parameters of the interaction (intra and interchain) to be essentially similar with the previously published parameters of alpha-phase. (C) 2004 Elsevier B.V. All rights reserved.