The purpose of this study was to examine cation channel activity in the apical membrane of the outer medullary collecting duct of the inner stripe (OMCD_i) using the patch-clamp technique. In freshly isolated and lumen-opened rabbit OMCD_i, we have observed a single channel conductance of 23.3 ± 0.6 pS (n = 17) in cell-attached (c/a) patches with high KCl in the bath and in the pipette at room temperature. Channel open probability varied among patches from 0.06 ± 0.01 at 60 mV (n = 5) to 0.31 ± 0.04 at 60 mV (n = 6) and consistently increased upon membrane depolarization. In inside-out (i/o) patches with symmetrical KCl solutions, the channel conductance (22.8 ± 0.8 pS; n = 10) was similar as in the c/a configuration. Substitution of the majority of Cl with gluconate from KCl solution in the pipette and bath did not significantly alter reversal potential (E_rev) or the channel conductance (19.7 ± 1.1 pS in asymmetrical potassium gluconate, n = 4; 21.4 ± 0.5 pS in symmetrical potassium gluconate, n = 3). Experiments with 10-fold lower KCl concentration in bath solution in i/o patches shifted E_rev to near the E_rev of K⁺. The estimated permeability of K⁺ vs. Cl was over 10, and the conductance was 13.4 ± 0.1 pS (n = 3). The channel did not discriminate between K⁺ and Na⁺, as evidenced by a lack of a shift in the E_rev with different K⁺ and Na⁺ concentration solutions in i/o patches (n = 3). The current studies demonstrate the presence of cation channels in the apical membrane of native OMCD_i cells that could participate in K⁺ secretion or Na⁺ absorption.