BACKGROUND/AIMS The follow-up strategy after hepatectomy for hepatocellular carcinoma (HCC) usually depends on the experience of physician, resulting in frequent imaging studies, which leads to increased cost. Hence, we investigated the role of monitoring alpha-fetoprotein (AFP) levels after hepatectomy in patients with preoperative high AFP. METHODS From January 2000 to December 2004, 66 patients who underwent curative hepatectomy due to HCC with preoperative AFP level > 400 ng/mL were reviewed. Changes in AFP level after the operation were investigated. The recurrence was suspected in case of two consecutive increase of AFP over cut-off value. Cut-off value was determined by ROC curve. All patients were divided into 2 groups: patients who met the definition (Group S) and those who didn't (Group D). RESULTS AFP level of 20 ng/ml was proposed as the cut-off value for diagnosis of recurrence by ROC curve. Thirty two patients who didn't have the AFP level decreased below 20 ng/ml after the resection had HCC recurred, whereas 16 out of 34 patients who had AFP decreased had tumor recurrence. The AFP level of patients without recurrence was kept below 20 ng/ml during the follow-up. The AFP level of 44 out of 48 recurred patients increased over 20 ng/ml upon recurrence. By definition, group D were 5 patients. In 4 patients of group D, the AFP level didn't increase above 20 ng/ml upon recurrence. These patients had HCC and they recurred 1 year after the surgery. CONCLUSIONS In patients with preoperative AFP level > 400 ng/ml, the AFP level tended to increase above 20 ng/ml at recurrence mostly within 1 year. Hence, we proposed that these patients could be monitored by only AFP until 1 year after surgery.