The activity coefficients at infinite dilution, gamma(infinity)(i), for 25 organic solutes, alkanes, alkenes, alkyl benzenes, acetonitrile, acetone, 1,4-dioxane, tetrahydrofuran, ethyl acetate, and chloromethanes, in the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) have been measured by the gas-liquid chromatographic method at temperatures from (303.15 to 363.15) K. The partial molar excess enthalpies at infinite dilution, H-i(E,infinity), of the solutes in the ionic liquid were also derived from the temperature dependence of the gamma(infinity)(i) values.