Objectives: This study aimed to evaluate the effects of histopathological findings observed in removed gastric tissues on the preoperative and postoperative hemogram data. Materials and Methods: Sixty patients with sleeve gastrectomy were included in the study. Histopathologic findings were compared with the hemogram values. Results: Preoperative hemoglobin (HGB) and hematocrit (HCT) values were significantly lower in patients with intestinal metaplasia (IM) compared to those without IM (p values 0.033 and 0.036, respectively). Preoperative red blood cell (RBC) and HCT values were significantly lower in women with Helicobacter pylori compared with those without H. pylori (p values 0.031 and 0.032, respectively). In contrast, in men with H. pylori, the preoperative RBC, HGB, and HCT values were significantly higher than those without H. pylori (p values 0.007, 0.031, and 0.027, respectively). Conclusion: We found that IM and presence of H. pylori had effects on hemogram values. We suggest that preoperative H. pylori assessment can yield use in the evaluation of postoperative anemia.