CD133 is one of the most important stem cell markers in solid cancers and Ki-67 is a marker that reflectscell proliferation. The relationships between the expression of CD133 and Ki-67 and prognosis in gastriccarcinoma are unknown and need exploring. We examined 50 gastric cancer patients retrospectively in theRadiation Oncology Department of the Faculty of Medicine, Gazi University. CD133 and Ki-67 expression wasexamined using immunohistochemical staining. The survival rate in patients with CD133 positive expressionwas significantly worse than that in the patients with negative expression (p=0.04). Expression of CD133 had apositive correlation with that of Ki-67 (r=0.350; p=0.014). Multivariate analysis revealed that the expression ofCD133 was an independent prognostic factor in gastric cancer (p=0.02). Conclusion, expression of CD133 maybe a useful prognostic marker in gastric cancer.