The enthalpies of solution of NaBr, NaI and NaClO4 in methanol + propylene carbonate mixtures were measured at 298.15 K. From these data, together with literature data that refer to (n-Bu)(4)NBr, (n-Bu)(4)NB(n-Bu)(4) and (n-Bu)(4)NClO4 the enthalpies of transfer of the individual ions Na+, Br-, I-, ClO4- and (n-BuN+, from methanol to methanol + propylene carbonate mixtures were calculated employing the assumption Delta(tr)H(infinity x)(n-BuN+ = Delta(tr)H(infinity)B(n-Bu)(4)(-). The dependences of the single-ion transfer enthalpies on the mixed solvent composition are discussed.