Purpose. This study examined the characteristics of fatigue and the relationship between fatigue and its related factors in Korean patients on hemodialysis. Methods. A cross-sectional correlational study was conducted with 104 patients on hemodialysis in Seoul, Korea. Finding. Of a total of 104 subjects, eighty-one ($77.9\%$) complained of fatigue. Fatigue severity was measured by the self-rating Visual Analogue Scale-Fatigue (VAS-F) with a mean score of 36.5 (SD = 17.49, range 2 - 81). The mean duration of fatigue was 3.8 hours (SD = 5.3, range 0 - 24). Depression was most significantly correlated with fatigue (beta = .43, p<.00), with interdialytic weight gain (beta = .25, p<.05) being the second most significant correlate. Conclusion. This study shows that nursing interventions for patients who experience fatigue while on hemodialysis should be focused on both psychological problems, such as depression, as well as on physiological problems, such as interdialytic weight gain.