Distal airways are believed to be a major site of disease in cystic fibrosis. The product of the CF gene, CFTR, is expressed in non-ciliated bronchiolar epithelial (Clara) cells. Clara cells in primary culture are capable of Cl⁻secretion which can be stimulated by cAMP and extracellular nucleotides. We used the patch clamp technique to look for Cl⁻channels in the apical membrane of rabbit Clara cells. In cell-attached patches, we recorded Cl⁻channels with a conductance for outward currents of 7.5 ± 0.4 pS (n = 10) and for inward currents of 3.2 ± 0.5 pS (n = 10); these channels typically exhibited slow kinetics and were not inhibited by the Cl⁻channel blockers NPPB and DIDS. Channel activity was not noticeably dependent on pipette potential. Addition of chlorophenylthio-cyclic AMP (cpt-cAMP) to the bath increased the percentage of cell-attached patches with active channels (33.8% vs 56.7%; p< 0.05) and the channel open probability (0.49 ± 0.03 vs 0.84 ± 0.02; p< 0.05). Extracellular ATP increased the percentage of cell-attached patches with active channels (28.7% to 50.0%; p< 0.05) but had no significant effect on the channel open probability (0.62 ± 0.07 vs 0.60 ± 0.06). In conclusion, rabbit non-ciliated bronchiolar epithelial cells express low-conductance Cl⁻channels that share many similarities with the CFTR-related Cl⁻channel and are regulated by cAMP and extracellular ATP.