Background Gastric cancer is one of the most common types of malignant tumors in China and East Asia and has the highest mortality rate of the malignant gastrointestinal tumors.Neoadjuvant chemotherapy is a systemic or local chemotherapy that is given prior to the local treatment of malignant tumors.Neoadjuvant therapy is currently showing some positive prospects; however,its clinical effects remain controversial.In this study,we used the modified FOLFO×7 (mFOLFO×7) regimen as a neoadjuvant chemotherapy regimen.Perioperative clinical and pathological efficacy,toxicity,effects of surgery,postoperative observation,and prognosis were studied to investigate its clinical efficacy and safety.Methods Eighty patients with advanced gastric cancer were treated in our surgery department from 2005 to 2009; 38 of these patients received mFOLFO×7 neoadjuvant chemotherapy,the other 42 patients assigned to the control group.The perioperative effects of mFOLFO×7 chemotherapy,including clinical effects and toxicity,were observed in each patient.Results After mFOLFO×7 chemotherapy,clinical and pathologic stages decreased in 21.1％ and 36.8％ of the patients,respectively,but the results were not statistically significant (P=0.129).The clinical response rate was 50％ (19/38).Toxicity was mild; most adverse events were grade I or ll and involved no severe infections or deaths.Compared with the control group,the radical resection rate increased (92.1％ vs.85.7％; P=0.437); surgical effects were completed without an increased incidence of perioperative complications.The 1-,2-,and 3-year survival rates were 78.70％,57.40％,and 51.66％,respectively,in the neoadjuvant chemotherapy group and 78.57％,56.87％,and 43.16％,respectively,in the control group.Conclusions The mFOLFO×7 regimen was very effective and well-tolerated as a neoadjuvant chemotherapy for advanced gastric cancer.However,the 1-,2-,and 3-year survival rates in the mFOLFO×7 group were not significantly different from the control group.