We describe successful resection of rapidly enlarging liver metastases from an alpha-fetoprotein-producing gastric cancer, as these usually carry a dismal prognosis. A 68-year-old woman underwent distal gastrectomy for an alpha-fetoprotein-producing gastric cancer without liver metastasis. The tumor was a moderately differentiated tubular adenocarcinoma with invasion of the muscularis propria. Venous and lymphatic invasion were noted, as was metastasis to lymph nodes along the greater curvature. Serum alpha-fetoprotein was 331 ng/mL before gastrectomy, decreasing to 18.6 ng/mL by postoperative day 28. At 2 months after operation, computed tomography detected no metastasis, but at 4 months alpha-fetoprotein increased to 2,190 ng/mL, and at 5 months liver tumors were detected by ultrasonography and computed tomography. Serum alpha-fetoprotein increased to 5,673 ng/mL, and serum PIVKA2 concentration was 18 mAU/ml just before operation. Extended left hepatectomy was performed. The resected specimen of segment 4 contained two well-defined tumors, measuring 5 x 4 cm and 2 x 2 cm, while that of segment 5 contained a similar-appearing tumor measuring 2 x 2 cm. The resected tumors had the same histologic appearance as the previously removed gastric cancer. The tumor cells were immunohistochemically reactive for alpha-fetoprotein. The postoperative course was uneventful, and the patient was discharged on postoperative day 15. Serum alpha-fetoprotein decreased to 20 ng/mL by postoperative day 15, and to 5 ng/mL by 2 months after operation. For 5 months since operation, no recurrence has become evident, and serum alpha-fetoprotein has remained within the normal range.