Objective: Gastric cancer consists of many histological subtypes. The prognostic value of histological types in stomach cancer is not well defined. In this study, we investigated the effects of different histological types on surgical and oncological outcomes in stomach cancer. Methods: Patients with a histology of undifferentiated carcinoma, neuroendocrine tumors, and gastrointestinal stromal tumors were included in the study of 1,060 patients who underwent gastrectomy for gastric cancer between 2010 and 2019. They were divided into three groups as group 1 (undifferentiated tumor), group 2 (neuroendocrine tumor), and group 3 (gastrointestinal stromal tumor). Demographic and clinical features, operative and oncological outcomes, and survival were compared between the groups. Results: Of a sample group that included 1,060 diseases, 53 patients (5%) were included in the study. Group 1 consisted of 24 patients, group 2 consisted of 10 patients, and group 3 consisted of 19 patients. Average age (p=0.591), was similar across all groups. Tumors were most frequently located in the corpus (41.7% vs. 80% vs. 42%, respectively) (p=0.283). Patients in group 1 and group 2 underwent total gastrectomy at a higher rate, with 79.2% and 60%, respectively, whereas in group 3, subtotal gastrectomy was performed on 63.2% of the patients. The number of lymph nodes dissected was highest in group 1 (24.25 vs. 13.70 vs. 9.52, p=0.00). The anastomosis leak (p=0.285) and post-operative 90-day mortality (p=0.285) were similar in each group. Local recurrence was most frequent in group 1 (50% vs. 40% vs. 10.5%, p=0.023). Total survival time was shortest in group 1 (31 months vs. 78 months vs. 99 months, p=0.005). Conclusion: While demographic characteristics, clinical features, and surgical results were not affected by tumor histology, oncological results (overall survey and local recurrence) were associated with tumor histology. Undifferentiated carcinoma showed an oncologically aggressive course compared to other histological types.