The incidence of gastric cancer in young has increased steadily in the last decades. Little is known about the clinicopathologic features and prognostic factors of young adult gastric cancer patients. The clinicopathological characteristics of 294 young adult gastric cancer patients between 20 and 50 years old were reviewed retrospectively from hospital records in Sun Yat-Sen University Cancer Center between 1996 and 2006. They were compared with 706 elder patients 51 years of age or over. A steady increasing in the proportion of female in the gastric carcinoma patients as the age decreasing was found. The distinguishing histological features of young adult patients were higher percentage of poorly differentiated grade and distant metastasis. The distribution of tumor-nodes-metastasis (TNM) stage was similar between these two groups. The 5-year disease-specific survival rate in the young adult group was significantly higher than in the elderly group. More patients receiving adjuvant chemotherapy were found in the young adult group. Multivariable analysis demonstrated that TNM stage and presence of angiolymphatic invasion were the independent negative predictors of survival for young patients with gastric cancer. Gastric cancer in young patients differs from that in elderly patients including a lack of male predilection, more aggressive histologic features, and better survival rate.