Activity coefficients at infinite dilution for 30 solutes (alkanes, alkenes, alkyl benzenes, ketones, chloromethanes, aromatic compounds, acetonitrile, formaldehyde, and ethyl acetate) in N,N'-di(2-ethylhexyl)isobutyramide have been determined at temperatures T = (323.15 to 373.15) K by inverse gas chromatographic technique. Net retention volumes of solutes have been measured as a function of temperature. From the temperature dependence of the activity coefficients at infinite dilution, partial molar excess enthalpies and activity coefficients at infinite dilution at 298.15 K of solutes in N,N'-di(2-ethylhexyl)isobutyramide have been derived. Selectivity values at infinite dilution have been computed from the activity coefficients at infinite dilution values.