Densities of binary mixtures of tetralin + toluene, + ethylbenzene, and + propylbenzene have been measured over the whole composition range at 298.15 and 308.15 K by using a vibrating-tube densimeter. Excess molar volumes V-E Of these binary mixtures are obtained from the measured densities. The values of V-E are negative over the entire range of composition for these mixtures.