Introduction The purpose of this study was to identify the frequency, severity, and risk factors of complications after open gastrectomy using the Clavien- Dindo classification because institution-specific criteria were mostly used in the previous articles. Materials and Methods All complication data were obtained from our prospectively collected database of open gastrectomy from January 1999 to December 2012 (n=539). Complications were classified into either major surgical complications such as pancreatic fistula, abdominal abscess, and anastomotic leakage, or others. Frequency and severity were graded retrospectively according to the Clavien- Dindo classification for subsequent analysis of risk factors. Results There were 222 events occurred in 156 patients (28.9%). Complications of grade IIIa or greater were 8.3% for major surgical complications and 10.6% for all complications. The mortality rate was 1.1%. Blood loss was the only independent risk factor for major surgical complications of grade IIIa or greater (odds ratio 1.923, 95% Confidence Interval 0.320-0.786, p=0.003). Total gastrectomy was the only independent risk factor for all complications of grade IIIa or greater (Odds ratio 2.075, 95% Confidence Interval 0.260-0.896, p=0.021). Disscussion The present study provided the objective overview regarding complications after open gastrectomy. Blood loss and total gastrectomy were revealed as the significant risk factors for complications.