A flow mixing microcalorimeter in conjunction with asymmetric syringe-type pumps was employed to measure enthalpies of mixing at 298.15 K for highly dilute aqueous solutions of 16 organic solvents of moderate hydrophobicity. Limiting partial molar excess enthalpies were determined by extrapolating these data to infinite dilution. Except for 2,4-pentanedione, the values of limiting partial molar excess enthalpies for all the examined mono- and bifunctional compounds containing hydroxy, keto, ether, ester, and nitrile groups are negative, indicating that the process of their dissolution in water is energetically favored at room temperature. Comparison with available literature data showed good agreement. Prediction of limiting partial molar excess enthalpies was tested for two group-contribution methods: that of Cabani et al. (J. Solution Chem. 1981, 10, 563-595) was found to be fairly good for monofunctional derivatives, but failed for the bifunctional derivatives, and the modified UNIFAC (Dortmund) yielded completely unsatisfactory results.