The present study was undertaken to determine serum adiponectin level in patients with cerebral infarction and to further analyze any difference in serum adiponectin levels among atherosclerotic disorders. One hundred fifty-two subjects with atherosclerotic disorders were enrolled, 110 males and 42 females, with the age of 67.0 ± 9.9 years (mean ± SD). They were divided into 62 patients with cerebral infarction, 48 patients with ischemic heart disease, and 42 patients with arteriosclerosis obliterans. Thirty-two subjects matched by age, gender, and body mass index served as controls. Serum adiponectin levels were 7.2 ± 0.6 μg/mL (mean ± SE) in the patients with cerebral infarction, 7.2 ± 0.8 μg/mL in those with ischemic heart disease, and 6.9 ± 0.9 μg/mL in those with arteriosclerosis obliterans. They were significantly less than the level of 12.6 ± 1.9 μg/mL in the control group (P < 0.01). However, there was no difference in serum adiponectin level among three groups of atherosclerotic disorders. In the patients with acute cerebral infarction, serum adiponectin level was temporarily reduced from 7.3 ± 0.9 to 6.2 ± 0.8 μg/mL 14 days after the hospitalization (P < 0.01), followed by recovery to the basal value. The present findings indicate that serum adiponectin levels are equivalently reduced in patients with atherosclerotic disorders, and that serum adiponectin is changeable under acute phase of cerebral infarction.