Wishing to extend its possibilities, we have used a CRMT rocking calorimeter associated with a microbomb to determine the enthalpy of combustion of a sample of low mass (about 7 mg) of a substance containing bromine. p-Bromobenzoic acid, p-BrC6H4COOH, a candidate as reference material for combustion calorimetry of substances containing bromine, has been investigated. The value of -(3090.1 +/- 1.3) kJ . mol(-1) for its molar enthalpy of combustion obtained with this apparatus is in very good agreement with the two literature values obtained by classical rotating-bomb combustion calorimetry (m approximate to 1 g for each combustion).