The described computer method of stroke volume (SV) estimation is based on impedance cardiography (ICG) signals. This method allows to calculate SV for 4096 successive cycles of the heart. The disturbing influence of respiration is reduced by base-line correction procedure. Stroke volume values determined automatically (AD) were compared with those obtained by conventional hand digitizing (HD) in 5 young male subjects in the supine and sitting positions, and in 5 subjects in the standing position. The correlation coefficient between SV values determined automatically SV (AD) and hand digitized SV (HD) calculated for all collected data was 0.9583 (n = 150, P less than 0.001). The error of the automatic SV determination was 6.7%.