Flow measurements of the right portal vein were performed in seven healthy volunteers with the segmented k-space fast gradient-echo phase-contrast (fcard-PC) sequence under breath-holding. The mean velocity and the flow rate of the right portal vein at maximal expiration, 14.3 +/- 4.4cm/sec and 457 +/- 218 ml/min, were significantly greater (p < 0.01) than those at maximal inspiration: 11.8 +/- 3.8cm/sec (mean +/- SD) and 364 +/- 191ml/min, respectively. Fcard-PC enabled flow measurements to be obtained under breath-holding. Using this technique, we demonstrated portal venous flow changes according to respiratory phase.