Using an isoperibol twin Dewar solution calorimeter, the enthalpies of reaction of normal lead 2, 4-dinitroresorcinol; mono basic lead 2, 4-dinitroresorcinol; tribasic lead 2, 4-dinitroresorcinol; quadrabasic lead 2, 4-dinitroresorcinol; monobasic lead 4, 6-dinitroresorcinol; dibasic lead 4, 6-dinitroresorcinol and tribasic lead 4, 6-dinitroresorcinol were determined as - 29.36; - 85.34; - 179.12; - 227.37; - 96.62; - 175.88 and - 162.47 kJ mol(-1), respectively, which, with various ancillary data, gave the standard enthalpies of formation of - 396.01; - 628.46; - 1397.37; - 1637.55; - 927.74; - 1132.95 and - 1434.83 kJ mol(-1), respectively.