Background: Laparoscopic gastrectomy has been a common tool for gastric cancer patients in eastern Asian countries. A large-scale prospective study with a sample size sufficient to investigate the benefit of laparoscopy-assisted distal gastrectomy (LADG) has never been reported. We conducted a multi-center phase II trial (JCOG0703) to evaluate the safety of LADG with nodal dissection for clinical stage I gastric cancer patients. A short-term outcome including postoperative complications of LADG as a result of this study was already reported and a following multi-center phase III trials (JCOG0912) to confirm the non-inferiority of LADG compared with open gastrectomy in terms of overall survival (OS) was already started. Long-term outcomes as the secondary endpoints of this study are reported here after 5-year follow up period. Methods: The subjects of this study comprised patients with clinical stage I gastric cancer that were able to undergo a distal gastrectomy. LADG with D1 plus suprapancreatic lymph node dissection was performed by credentialed gastric surgeons who experienced >=30 LADG and >=30 open gasterctomy. The primary endpoint was the proportion of patients who developed either anastomotic leakage or a pancreatic fistula. The secondary endpoints included surgical morbidity, short-term clinical outcome, OS, and relapse free survival (RFS). Results: Between November 2007 and September 2008, 176 eligible patients were enrolled. 140/23/9/4 patients had pStage IA/IB/II/IIIA disease respectively. No patients had recurrence. 3 patients died without recurrence. 5-year OS was 98.2% (95%CI, 94.7% to 99.4%). 5-year RFS was 98.2% (95%CI, 94.4% to 99.4%). Conclusions: The long-term outcome of LADG for Stage I gastric cancer patients seem comparable to those of open procedures. However, this result should be confirmed by a randomized control trial. We have just finished an accrual of 921 patients for a multi-center phase III trial (JCOG0912) to confirm the non-inferiority of LADG compared with open gastrectomy in terms of OS. Clinical trial information: UMIN000000874.