['A few studies have shown that elevated CA-125 levels are associated with chronic obstructive pulmonary disease (COPD). However, there are no data concerning the associaton between serum CA-125 levels and right ventricular (RV) function in COPD patients. This study aimed to evaluate the relationship between CA-125 level and RV echocardiographic parameters in COPD patients.', 'Fifty-two patients with COPD (39 male/13 female, mean age 68.9 ± 5.7 years) were studied. The control group consisted of 30 age-sex matched healthy volunteers (23 male/7 female, mean age 64.2 ± 6.3 years). Patients were divided into two subgroups: patients without pulmonary hypertension (group I, n = 25) and with pulmonary hypertension (group II, n = 27). Conventional echocardiographic parameters, tissue Doppler imaging (TDI) and CA-125 level measurements were performed in all subjects.', 'Patients in group II had significantly higher CA-125 levels than those in group I and controls (P < 0.01). CA-125 levels in group I were also higher than control group (P < 0.05). CA-125 levels were correlated with left ventricle E/A ratio, systolic pulmonary artery pressure (sPAP), RV myocardial performance index, and RV fractional area change (r = 0.37, 0.56, 0.34, and -0.42, respectively, all with P < 0.05). There was an independent correlation between CA-125 levels and sPAP values (β = 0.76, P < 0.001).'] Is cA-125 level associated with right ventricular echocardiographic parameters in patients with COPD?