Akaline-earth plumbates are important accessory phases in {(bismuth, lead) + strontium + calcium + copper + oxygen} ("BSCCO") high-temperature superconductor materials. Reliable values for standard molar enthalpies of formation (Delta(f)H(m)(0)) of the plumbates are therefore an essential part of the BSCCO high-temperature superconductor the modynamic data base. To obtain Delta(f)H(m)(0) of SrPbO3 and Sr2PbO4, we measured the enthalpies of solution of SrO, PbO2, SrPbO3, and Sr2PbO4 in 6 mol . dm(-3) HCl by isoperibol solution calorimetry and derived the values of Delta(f)H(m)(0) for the strontium plumbates from Hess cycles. The values obtained were Delta(f)H(m)(0)(SrPbO3, 298.15K) = -(949.3 +/- 3.5)kJ . mol(-1) and Delta(f)H(m)(0)(Sr2PbO4, 298.15K) = -(1565.1 +/- 6.9) kJ . mol(-1). In previous experiments, we measured the total vapor pressures over SrPbO3 by Knudsen effusion vacuum thermogravimetry. In the present paper, these data were used for an independent derivation of Delta(f)H(m)(0)(SrPbO3, 298.15 K) via a van't Hoff extrapolation, which yielded - (945.8 +/-7.5) kJ . mol(-1), in good agreement with the value obtained calorimetrically. Our determination of Delta(f)H(m)(0) (Sr2PbO4, 298.15 K) agrees well with a recently published value obtained from electrochemical measurements. Published by Elsevier Science Ltd.