Background: The purpose of this article was to evaluate the accuracy and reproducibility of spiral computed tomography (CT) and the curved line and cubic spline algorithms in measuring liver volume. Methods: Spiral CT was performed in phantoms, cadaveric liver specimens, and 35 live human subjects (19 healthy volunteers and 16 patients). Images were transferred to a workstation, and volumes were measured by two observers. One observer repeated the measurements at a separate sitting. Results: The correlation between the CT measurement and the gold standard measurement of the cadaveric livers was very strong (r Å 0.94). For the live human subjects, the intraobserver and interobserver correlations were extremely high (r Å 0.999 and 0.997, respectively). The mean difference in liver volume measurements between the separate observations was 1%. Conclusion: The accuracy and reproducibility of this method of assessing liver volume are very high.