Hydrated strontium borate, SrB4O7 center dot 3H(2)O, has been synthesized and characterized by XRD, FT IR, DTA-TG and chemical analysis. The molar enthalpy of solution of SrB4O7 center dot 3H(2)O in 1 mol dm(-3) HCl(aq) was measured to be (21.15 +/- 0.29) kJ mol(-1). With incorporation of the previously determined enthalpies of solution of Sr(OH)(2)center dot 8H(2)O(s) in [HCl(aq) +H3BO3(aq)] and H3BO3 in HCl(aq), and the enthalpies of formation of 1420(1), Sr(OH)(2)-8H(2)O(s) and H3BO3(s), the enthalpy of formation of SrB(4)O7 center dot H2O was found to be -(4286.7 +/- 3.3) kJ mol(-1). (c) 2008 Elsevier B.V All rights reserved.