The retention of some 2 dozen nonsllanophilic solutes on reversed-phase bonded phase columns has been correlated by the solvatochromic comparison method. In accord with other related studies, the most Important solute parameters, which influence retention, are Its size and hydrogen bond basicity but not hydrogen bond acidity. The solute's dipolarity Is a minor but still significant factor. Retention as a function of the nature of the bonded phase (hydrocarbon vs. fluorocarbon), mobile phase modifier (methanol, acetonltrlle, tetrahydrofuran), and composition (70/30 methanol-water to 30/70 methanol-water) has been studied using literature and original data as the basis set for the correlations. The results obtained show the best fits of any linear solvation energy relationship thus far observed in correlating many different data with solvatochromie parameters.