Rationale: Patients with gastrointestinal stromal tumors (GISTs) are often found to have liver metastases at their 1st presentation. Most patients need preoperative treatment to reduce the size of the liver metastases to increase the possibility of surgical resection. Currently, imatinib mesylate is the drug of 1st choice for preoperative treatment and sunitinib malate (SM) is seldom used. Here we report a case of GIST with liver metastases where SM was used as a preoperative treatment. Patient concerns: A 56-year-old worker presented with intermittent abdominal pain and eating difficulties. Diagnoses: An enhanced computed tomography scan showed a 15 x 15 x 10 cm malignant mass in the upper abdomen, and 2 metastases (15.1 x 13.1 cm and 14.8 x 8.8 cm) in the liver. The postcaval and middle hepatic veins were compressed by the liver metastases, making radical resection very difficult. Interventions: First the primary tumor in the jejunum was resected, and then SM was used as a preoperative treatment to reduce the size of the liver metastases to improve the possibility of surgical resection. Outcomes: Both liver metastases regressed considerably in size and it was then possible to perform a radical resection. Lessons: The SM has the potential to be used as preoperative therapy for GIST with large liver metastases. This method provides a new option for the preoperative treatment of GIST with liver metastases.