BACKGROUND Evaluation of hyperthermic intraperitoneal chemotherapy (HIPEC) in reducing metachronous peritoneal metastases (MPM) risks in patients with resectable serosa-invasive gastric cancer. METHODS Between 2008 and 2016, 154 patients with gastric cancer (stage IIB-IIIC) were randomly assigned to two groups: 76 patients underwent HIPEC (cisplatin 50 mg/m2 + doxorubicin 50 mg/m2, 42 °C, 1 h) combined with radical surgery (HIPEC group) and 78 patients underwent only radical surgery (control group). RESULTS Evaluation of HIPEC toxicity showed neither toxic complications of IV-V degree nor haematological toxicity (according to CTCAE v. 4.03). There was no significant difference in the rate of complications between the two groups (p = 0.254). There was a more frequent disease progression in the control group than in the HIPEC group: 42/55 patients (76.4%) vs. 36/68 patients (52.9%), respectively (p = 0.009). At the same time a significant decrease in the rate of MPM was observed after HIPEC administration as compared with surgery alone - 16/68 (12.8%) vs. 39/55 (27.6%) (p < 0.001). 3-year progression-free survival was 47% (95% CI 36-61)) in the HIPEC group and 27% (95% CI 17-43) in the control group - p = 0.0024. The N-stage, HIPEC procedure, type of surgery and interaction between HIPEC treatment and age were independent prognostic factors. CONCLUSIONS HIPEC appears to be helpful in improving treatment results in radically operated gastric cancer patients.