Background: The prognosis of gastric cancer patients remains poor even after radical surgery. Although local control and survival are significantly improved by postoperative CRT, treatment compliance is frequently compromised due to severe toxicity. On the other hand, treatment compliance is good with preoperative chemotherapy (CT) in gastric cancer and preoperative CRT in esophageal cancer. The current study was initiated to investigate the feasibility and efficacy of preoperative CRT for marginally resectable and initially irresectable gastric cancer. Methods: Patients with marginally resectable and initially irresectable gastric cancer, without signs of peritonitis carcinomatosa, stage IB-IV(M0) were treated with CRT. Treatment consisted of irradiation to a total dose of 45 Gy given in 25 fractions of 1.8 Gy combined with concurrent weekly carboplatin (AUC 2) and paclitaxel (50mg/m²) on days 1, 8, 15, 22 and 29 of irradiation, followed by standardized surgery 4-6 weeks after the last irradiation. Results: Between December 2007 and January 2012, 25 patients with stage II-IV(M0) marginally resectable (n=13) or initially irresectable gastric cancer received preoperative CRT. One patient discontinued concurrent CT in the 4^th week due to toxicity, but completed radiotherapy, and another patient stopped CRT after the 3^rd week due to progressive disease. During CRT, grade III gastrointestinal adverse events (AE) occurred in 3 patients (12%), grade III hematological AE in 3 (12%) and grade III other AE in 2 (8%). Twenty-four patients (96%) were operated following CRT. Surgery-related complications consisted of anastomotic leakage in 3 patients (12%) and bowel perforation in 2 (8%). Postoperative mortality was 4%. A microscopically radical resection was achieved in 18 patients (72%), 8 of whom had initially irresectable gastric cancer. The pathologic complete response rate was 16% (4/25 patients). Conclusions: In this study, preoperative CRT for marginally resectable and initially irresectable gastric cancer was associated with manageable toxicity and resulted in an encouraging pathologic response rate. A multicenter phase II study has recently been initiated.