OBJECTIVE To verify the possible association between the levels of serum ferritin and the degree of obstructive coronary artery disease. METHODS 115 patients with coronary arteriography and concomitant evaluation of serum ferritin were studied. The adopted cut-off values were 80 ng/ml for women and 120 ng/ml for men. RESULTS The mean ferritin levels for males and females were 133.9 +/- 133.8 ng/ml and 214.6 +/- 217.2 ng/ml, respectively (p=0.047). It was observed that 44.1% of the women had normal serum ferritin levels in comparison to 30.9% of the men (p=0.254). In the patients without obstructive coronary artery disease or with less severe obstructions (group A) the serum ferritin level was 222.3 +/- 325 ng/ml. On the other hand, for those with moderate (group B) and severe obstructions (group C) the levels were 145.6+-83.7 ng/ml and 188.9 +/- 150.6 ng/ml, respectively. There was no correlation between the degree of coronary artery disease and the mean level of serum ferritin. Regarding the cut-off value, the number of women with serum ferritin level > 80 ng/ml in groups B+C or only C was significantly higher than the number of women in group A (ODDS RATIO 9.71 with 95%CI from 1.63 to 57.72). For males there was no significant difference between the number of cases above or below the cut-off values (ODDS RATIO 0.92 with 95%CI from 0.28 to 2.95). CONCLUSIONS It was verified that women with serum ferritin levels > 80 ng/mL presented more severe obstructive coronary artery disease than women with lower levels. In men, the serum ferritin level was not a predictor element of the degree of obstruction.