Densities of mixtures of 1-butyl-3-methylimidazolium hexafluorophosphate, ([BMIM][PF6]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) with acetonitrile over the entire composition range at T = (293.15 to 343.15) K and with benzene and 1-propanol over the miscible composition range at T = (293.15 to 343.15) K were measured by a vibrating tube densimeter. Density measurements were used to compute the excess molar volumes, V-E. The V-E values have been fitted to the Redlich-Kister equation. V-E values are negative for all the mixtures over the miscible range and become more negative with increasing temperature. The V-E values for benzene mixtures are the most negative in the investigation.