Pulmonary valve echography was technically possible in 44 of 120 patients with chronic lung disease (CLD). Mean pulmonary arterial pressure (Ppa) was significantly correlated with right ventricular isovolumetric relaxation ratio (RVIRT/RVET) as derived from the movement of cusps in valves of the right heart (r = 0.842; p less than 0.001). Prolonged RVIRT was found in 52% of patients with Ppa greater than 20 mmHg and in all ten patients with Ppa greater than 35 mmHg. Other echographic signs, including abnormal right ventricular systolic time intervals (STI), 'a' wave amplitude, right to left ventricular ratio (RV/LV) and interventricular septum diastolic bulging (IVS-B), were less sensitive, but found more often; when higher Ppa was recorded at catheterization in a given patient (r = 0.869; p less than 0.001). Approximate echographic estimation of Ppa in patients with chronic lung disease is possible if right ventricular systolic and diastolic time intervals can be measured and if abnormalities in right ventricular dimensions, interventricular septum motion and pulmonary valve echogram are considered. In contrast to pulmonary fibrosis, technical problems in adequate visualization of right heart valves in chronic obstructive lung disease limit the use of M-mode echo assessment of Ppa to a clinically unacceptable 22% of subjects.