The extent of right heart strain determines the prognosis of chronic lung disease. The value of a simple semiquantitative echocardiographic grading system for cor pulmonale was assessed in 69 patients (24 females, 45 males, age 61 +/- 12 years, ranging from 28-82 years) suffering from chronic lung disease. The patients were classified by echocardiography into four groups, Grade 0 consisting of those without evidence of right heart strain and three groups showing increasing severity of change (Grade I: right ventricular hypertrophy; Grade II: I + right ventricular dilation; Grade III: II + Dilation of the inferior vena cava). Echocardiographic investigation, at least from the subcostal view, and grading was possible in all patients. A correlation was found between the echocardiographic grading and the mean pulmonary artery pressure (PAP)-normal echo study 15.7 +/- 4.8; grade I 21.1 +/- 5.6; grade II 28.8 +/- 10.2; grade III 39.4 +/- 9.4 mmHg. In addition, patients with stress-induced pulmonary hypertension (PHT) were detected by Doppler echocardiography. 6 of 11 patients with latent PHT already showed evidence of cor pulmonale (4 Grade I and 2 Grade II). In 42 patients (61%) the systolic PAP was estimated by measuring the velocity of the tricuspid insufficiency jet with Doppler, and these data correlated closely with the invasive data (p < 0.001; r = 0.81). Doppler echocardiography for evaluation of cor pulmonale is feasible even in patients with chronic lung disease and limited acoustic windows. Semiquantitative grading correlates well with invasive data. Here, this technique is useful as a baseline study as well as for the follow-up of patients with chronic lung disease.