The BaPdS2 mixed palladium sulfide has been synthesized by direct reaction of a stoichiometric mixture of the PdS and BaS binary constituent sulfides. The standard molar enthalpies of formation of BaPdS2 and LaPd3S4 mixed sulfides were determined by the method of direct reaction calorimetry through synthesizing the respective compounds in a calorimetric cell from the stoichiometric mixture of appropriate starting materials. Combining the experimental results with the reference data for the starting materials, we found Delta(f,298)H(m)(0)(BaPdS2) = -515.4 +/- 16.8 kJ mol(-1); and Delta(f,298)H(m)(0)(LaPd3S4) = -817.6 +/- 43.8 kJ mol(-1).