Cystic Fibrosis (CF) pathology is attributed to a basic defect in epithelial anion transport. The loss of bicarbonate (HCO3−) transport in CF plays a critical role in pathogenesis by interrupting the normal formation and release of mucins in exocrine tissues as in pancreas, liver and intestines in CF, we do not know whether HCO3− secretion occurs in normal human native small airways, the most prevalent site of morbidity and mortality in CF. Using our recently developed mini‐Ussing chamber system to determine the properties of HCO3− transport in freshly dissected human airways (diameter ≈ 2.0 mm). We assayed HCO3− transport by measuring the transepithelial potential, conductance and equivalent short circuit current with bilateral 25 mM NaHCO3− plus 125 mM NaGlu in presence of luminal amiloride. Under these conditions since the only major transportable anion present was HCO3−, we took the short‐circuit current to be a direct measure of HCO3− transport in small airways. Applying selective agonists and/or inhibitors, we show that human native small airways constitutively secrete HCO3−, and could be further stimulated agonists mediated by cAMP (adrenergic) and Ca2+ (purinergic) and respectively inhibited by selective antagonists. These results suggest at least two pathways for HCO3− secretion, one dependent on Cystic fibrosis transmembrane conductance regulator (CFTR) and another dependent on a calcium‐activated chloride channel (CaCC), that secrete HCO3− into the airway luminal surface liquids, to critically support the discharge of mucins and maintain airway surface liquid pH for optimal defense and hygiene of small airways. By analogy with other organs in CF, failure to secrete HCO3− likely results poor mucociliary and pathogen clearance and thus should be seen a new target for therapy in CF and possibly other airway diseases.Support or Funding InformationSupported by the Nancy Olmsted Trust, the Cystic Fibrosis Foundation and Cystic Fibrosis Research, Inc.