Background: Conversion surgery could be an option for unresectable stage IV gastric cancer when distant metastasis (M1) is disappeared by chemotherapy. However, the indication and the optimal timing of conversion surgery in stage IV gastric cancer remain unclear, even if metastatic lesions disappear with chemotherapy. Guideline of National Comprehensive Cancer Network also shows no principle after down-staging. Methods: This retrospective study examined 34 gastric cancer patients who underwent curative conversion surgery at our institute between 2005 and 2014. Clinicopathologic characteristics and patient outcomes were analyzed, with particular focus on the potential to select patients who might benefit from surgical resection. Results: The number of M1 factors was one in 31 patients and two in 3, including metastases to non-regional lymph node in 21, peritoneum in 8, liver in 5, and lung in 3. The regimen of chemotherapy was Docetaxel/CDDP/S-1 in 23 patients, Docetaxel/CDDP/S-1+Trastuzmab in 6, S-1/CDDP in 2, Docetaxel/S-1 in 1, CPT/CDDP in 1, and S-1 monotherapy in 1. The median duration from initiation of chemotherapy to the operation was 114 days (range 37-653 days). Total gastrectomy was performed in 27 patients and distal gastrectomy was performed in 7 patients. Complete resection with no residual tumor (R0) was achieved in 23 of 34 patients, microscopic residual tumor status (R1) in 10, and macroscopic residual tumor (R2) in 1. The 3-year overall survival (OS) rate among the patients who underwent conversion therapy was 58.0% with MST of 1190 days. Univariate analysis among the patents with conversion surgery identified intestinal differentiation, pathological response grade≧1b, R0 resection as significant prognostic factors. Patients operated on more than 91 days from initiation of chemotherapy had the 3-year survival rate of 68.2%, compared to 40.0% for patients operated on less than 90 days. Conclusions: Our data demonstrate the increased 3-year survival rate associated with delayed conversion surgery for stage IV gastric cancer. Delayed conversion surgery should be considered for patients, even if metastatic lesions disappear with chemotherapy.