Objectives: We sought to assess the effects of blood donation on different echocardiographic parameters in healthy volunteers. Methods: A total of 101 healthy male volunteers were evaluated by echocardiography before and immediately after a 500-mL blood donation. In addition to traditional Doppler indices of left ventricular filling, Doppler tissue, color flow propagation, strain (E), and E rate were measured. Results: There was a statistically significant decrease in mitral peak E and A values after blood donation (E wave 0.85 +/- 0.12 vs 0.79 +/- 0.14 cm/s, P = .01; A wave 0.65 +/- 0.10 vs 0.60 +/- 0.12 cm/s, P = .05). Mitral color flow propagation velocity was not affected (560 +/- 123 vs 571 +/- 132 mm/s, P = not significant). There were no significant differences in the Doppler tissue parameters of peak systolic, and early and late diastolic velocities after blood donation (Sm 13.5 +/- 4.6 vs 13.3 +/- 4.9 cm/s, P not significant; Em 15.5 +/- 4.9 vs 15.9 +/- 5.1 cm/s, P not significant; and Am 14.1 +/- 3.9 vs 14.1 +/- 3.5 cm/s, P = not significant, respectively). The peak systolic E decreased significantly (- 28 +/- 8% vs - 21 +/- 4%, P = .03) whereas the peak systolic E rate was not affected (1.5 +/- 0.35 vs 1.4 +/- 0.40 s(-1), P = not significant). Conclusion: In healthy male volunteers, preload reduction induced by a 500-mL blood donation does not affect the color propagation velocity, E rate, and Doppler tissue velocities.