Vascular calcification (VC) is highly prevalent and predicts cardiovascular mortality in dialysis patients. The mechanisms are still unclear. Inflammation is a well-known inducer of VC. YKL-40 has been suggested as a novel biomarker of inflammation and has been demonstrated to be associated with cardiovascular mortality in hemodialysis patients. This study aims to evaluate the relationship between serum YKL-40 and VC in hemodialysis (HD) patients.A total of 109 HD patients and 31 healthy controls were enrolled in the study from September 2014 to December 2014. We evaluated the abdominal aortic calcification (AAC) score by plain X-ray films of the abdomen and measured serum YKL-40 concentrations using enzyme-linked immunosorbent assay. We also examined the relationship between YKL-40 levels and AAC scores in HD patients.Serum YKL-40 levels in HD patients were significantly higher than those in healthy controls [199.8 (144.8, 288.7) vs. 71.9 (52.8, 89.3) ng/ml; P < 0.001]. There was a tendency that YKL-40 levels in diabetic hemodialysis patients were higher than those in nondiabetic patients [217.8 (155.3, 335.8) vs. 192.9 (135.9, 274.4) ng/ml; P = 0.093]. A significant positive correlation was found between serum YKL-40 level and AAC score in these patients (r = 0.410, P = 0.003). Multiple regression analysis showed that Ln(YKL-40) was independently associated with AAC score in HD patients (P = 0.044).This study showed high serum YKL-40 concentrations in chronic HD patients and that YKL-40 was independently associated with increased AAC in hemodialysis patients.© 2024. The Author(s), under exclusive licence to Springer Nature B.V.