Objectives: To investigate and discuss the total-, lipid-associated, and thrombocyte-sialic acid levels in chronic heart failure (CHF) patients. Design and methods: Thirty-one chronic heart failure patients and 38 healthy controls were included in the study. Serum total sialic acid (TSA), lipid associated sialic acid (LASA), thrombocyte sialic acid (TrSA) were determined together with the traditional inflammation and prognostic markers. Results: Serum TSA levels were significantly higher in patient group (3.08 ± 0.33 mmol/L) than control group (2.60 ± 0.17 mmol/L). Serum LASA, homocysteine, high-sensitivity CRP, brain natriuretic peptide and erythrocyte sedimentation rate were also significantly higher in patient group. TrSA levels were not significant between the groups. Conclusion: TSA and LASA levels increase in CHF, independent from coronary artery disease. TrSA levels were not found to be a prognostic or valuable marker for CHF patients. Acute phase response and lipid associated portions of SA are thought to be responsible for SA rise in CHF. © 2009 The Canadian Society of Clinical Chemists.