BackgroundThe aim of the study was to determine the value of synchronous liver resection in patients with oligo-metastatic gastric cancer and the prognostic factors in these patients.Patients and methodsWe compared the results of 21 gastric patients with liver metastases and synchronous liver resection (LMR) to 21 propensity score-matched patients with gastric cancer and liver metastases in whom liver resection was not performed (LM0) and to a propensity score-matched control group of 21 patients without liver metastases and stage III and IV resectable gastric cancer (CG).ResultsThe overall 5-year survival of LMR, LM0 and CG were 14.3%, 0%, and 19%, respectively (p = 0.002). Five-year survival was 47.5% for well-differentiated tumour compared to 0% in patients with moderate or poor tumour differentiation (p = 0.006). In addition, patients with R0 resection and TNM stage N0–1 had a significantly better survival compared to patients with TNM N stage N2–3 (5-year survival: 60% for N0–1 vs. 7.7% for N2–3; p = 0.007).ConclusionsThe results presented in the study support synchronous liver resections in gastric patients and provide additional criteria for patient selection.