Density in the temperature interval (293.15 to 323.15) K and excess enthalpy at 303.15 K are determined for 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] + ethanol or + nitromethane and 1-butyl-3-methylimidazolium methylsulfate [BMIM][MeSO4] + ethanol or + nitromethane. Excess molar volumes are calculated at several temperatures from density data. Both excess properties are fitted to a Redlich-Kister-based equation, and results are discussed in terms of the chemical nature of the compounds that form the mixtures.