Densities of solutions of sodium tetraphenylborate, tetraphenylphosphonium bromide, sodium bromide, and sodium perchlorate solutions in N,N-dimethylacetamide and N,N-dimethylformamide have been measured over the concentration range of (0.015 to 0.40) mol.kg(-1) at temperatures between T = 283.15 K and T = 333.15 K. From densities, apparent molar volumes and partial molar volumes of the salts at infinite dilution as well as the expansibilities have been evaluated. Moreover, the apparent molar isentropic compressibility of all electrolytes has been determined from sound velocity measurements at T = 298.15 K. The limiting apparent molar compressibilities have been discussed in terms of possible methods of splitting them into ionic contributions.