Background:  ERS guidelines 2020 recommend further studies to define biomarkers to predict treatment response in chronic cough (CC) Aim: to identify a CC endotype based on the eosinophilic inflammation, regardless of the underlying disease, in order to detect a chronic cough marker. Methods: a retrospective analysis of consecutively admitted patients to a CC dedicated clinic to assess whether a peripheral blood eosinophil count (EOS) >150/mcl is linked to CC and to identify a CC endotype. Inclusion criteria were age>18, no antitussive treatment for at least 4 weeks, non-smoking (for at least 1 year) and normal chest x-ray Exclusion criteria: ACE inhibitor therapy, use of oral steroids, interstitial lung diseases, malignant diseases, TB  or nonTB active infections. Strength of the association  was estimated in terms of odds ratios (OR) with a 95% confidence interval (CI) and significant p-value <0.05 Results: 458 patients were included, 152 (33.1%) with EOS > 150/mcl, 269 (59%) Female median age of 61 (range 18?93). Concomitant diagnosis were asthma (52%), GERD (36%), rhinosinusitis (25%), COPD (15%), bronchiectasis (15%) and diabetes (7%). Patients with chronic cough, EOS>150/mcl and specific comorbidities showed increased Odd Ratio: COPD and rhinosinusitis OR 5.61 (CI 1.47-21.47) p=0.01, Asthma and Rhinosinusitis OR 1.83 (CI 1.16-2.87) p=0.009 Conclusions: One third of patients with CC and allergic asthma, allergic rhinosinusitis, asthma with rhinosinusitis or COPD with rhinosinusitis showed EOS > 150/mcl. Airway eosinophilic inflammation represent a potential target to improve CC on top of current treatment for underlying comorbidities.