A process is proposed for the separation of C.sub.5+ cuts by distillation into a low-boiler (A), a medium-boiler (B) and a high-boiler fraction (C) in one or more dividing-wall columns (TK), in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper, common column region (1), a lower, common column region (6), a feed part (2, 4) with rectifying section (2) and stripping section (4), and a withdrawal part (3, 5) with rectifying section (5) and stripping section (3), with feed of the C.sub.5+ cut (A, B, C) into the central region of the feed part (2, 4), discharge of the high-boiler fraction (C) from the bottom of the column, discharge of the low-boiler fraction (A) via the top of the column, and discharge of the medium-boiler fraction (B) from the central region of the withdrawal part (3, 5), wherein the dividing ratio of the liquid reflux at the upper end of the dividing wall (T) is set in such a way that the proportion of high-boiling key components in the liquid reflux over the stripping section (3) of the withdrawal part at the upper end of the dividing wall (T) is from 10 to 80%, preferably from 30 to 50%, of the limit value allowed in the medium-boiler fraction (B), and wherein the heating power in the evaporator at the bottom of the dividing-wall column (TK) is set in such a way that the concentration of the low-boiling key components in the liquid at the lower end of the dividing wall (T) is from 10 to 80%, preferably from 30 to 50%, of the limit value allowed in the medium-boiler fraction (B).