Objective To detect plasma brain natriuretic peptide changes in hemodialysis patients and assess the diagnostic value of BNP for cardiac dysfunction. Methods Plasma BNP concentration was measured in 45 hemodialysis patients and 32 healthy control subjects. Left ventricular end diastolic diameter (LVDd) and left ventricular ejection fraction (LVEF) were determined before dialysis, and comparing the relationship between the levels of plasma BNP and cardiac function. Results (1) The plasma BNP levels in normal controls were (4.6±2.7)pg/ml and (158.4±24.5)pg/ml and (97.5±16.8) pg/ml in 45 patients before and after hemodialysis, respectively, showing significant difference among those 3 groups (P<0.01). The plasma BNP levels in patients complicated by heart failure (LVEF<50%) before and after hemodialysis were (669.2±120.7)pg/ml and (224.2±43.8)pg/ml respectively, significantly higher than (72.7±13.3)pg/ml and (22.4±6.9)pg/ml in patients with normal cardiac function (LVEF≥50%) (P<0.01). The plasma BNP levels in patients with dilated left ventricle before and after hemodialysis were (612.4±101.5)pg/ml and (304.2±38.7)pg/ml respectively, significantly higher than (69.8±12.2)pg/ml and (21.7±7.1)pg/ml in patients with normal left ventricle. Multiple linear regression analysis for left ventricular diastolic dimension, LVEF and plasma BNP level before hemodialysis showed that high BNP level was significantly correlated with dilated left ventricle and poor cardiac function (P<0.01). Conclusion BNP concentration may be used as a biochemical marker of liquid overload and chronic cardiac failure in hemodialysis patients.