The sensitivity, specificity and diagnostic accuracy of 34 ECG-indices for right ventricular hypertrophy was checked up in 131 individuals--40 healthy, 59 with post mortem confirmed right ventricular hypertrophy and 32 with clinical and X-ray data for right ventricular hypertrophy. The following indices showed the best diagnostic value: AQSR to the right of + 90 degrees (in adults over 30); RV1 greater than or equal to 5 mm; SV5 or V6 greater than or equal to 7 mm: R/SV1 greater than or equal to 1 and/or R/SV5, V6 less than or equal to 1: RV1 + + SV5 or V6 greater than 10,5 mm; SV1 less than 2 mm: pathological progression of R/S in precordial leads to the right of the intermediate zone; R/S less than 1 and S greater than 4 mm in 1 st lead: TV1--V3--negative; P-pulmonale. That complex reveals accurately 60--70 per cent of the cases wi h right ventricular hypertrophy in mitral stenosis and chronic right heart. The false positive diagnosis is 5--10 per cent.