As the role of oxidative stress on human diseases, including the cardiovascular system disorders, has accentuated, the ultimate need of reliable markers of oxidative stress becomes more imperative. We aimed to measure: activities of HDL-associated antioxidant enzymes, paraoxonase (PON1) and arylesterase (ARE); total oxidative (TOS) and antioxidative status (TAS), in heart failure (HF) patients, and search for correlations of these markers. The study group consisted of 70 subjects with HF. The patients were classified in three groups according to the suggestions of New York Heart Association. Serum levels of PON1, ARE, TOS, TAS, brain natriuretic peptide (BNP), uric acid (UA), creatinine, and lipid parameters were determined. The oxidative status index (OSI) was calculated. Plasma PON1 activity was significantly decreased (p=0.04), while BNP and UA levels were significantly increased(p<0.0001, p= 0.03, respectively), with the severity of the disease. ARE, TAS, TOS, and OSI did not show any statistically significant difference. Statistical analysis showed negative correlation between PON1, ARE activities and BNP; positive correlation between disease duration, UA and BNP. Also, a positive correlation was determined between TAS and UA. We report for the first time a notable relationship between HDL-associated anti-oxidant PON-1 activity and New York Heart Association classification for HF .These prominent results provide further support for the role for oxidative processes in the disease progression of HF and for the anti-oxidant compensatory role of HDL. We believe in the potential of antioxidant medications in HF and promote proper oxidative stress markers in routine use in diagnosis and follow-up.