Introduction: Chronic cough is a common complaint, accounting for one third of all referrals to chest physicians. National and international guidelines exist for treatment and investigation, despite this, in upto 42% of patients, no cause for cough is found. Whether this represents undiagnosed pathology, inadequate treatment or 'idiopathic cough' is unclear. Gastro-oesophageal reflux is reported as a common cause of chronic cough but the exact mechanism by which this occurs is unclear. Both direct cough receptor stimulation (microaspiration and LPR), and indirect stimulation (an oesophago-tracheo-bronchial reflex) have been proposed. Methods: 100 chronic cough patients have been comprehensively investigated, incorporating routine bronchoscopy and oesophageal impedance/pH into the diagnostic algorithm. Cough has been evaluated, both before and after treatment, by subjective assessment and objective cough sound monitoring. Results: Subjective assessment of cough was found to be affected by patient anxiety and depression and related only moderately to cough frequency.