Purpose: We aimed to investigate the effect of oral Saccharomyces cerevisiae Hansen CBS 5926 therapy (Saccharomyces boulardii) on gastrointestinal symptoms and nutrition in gastrectomized patients. Materials and Methods: Ninety patients who underwent a gastrectomy due to early gastric cancer were randomly divided into case and control (placebo) groups and were given medicine or placebos for 12 weeks. The gastrointestinal symptom rating and the nutritional status were evaluated by using double blind methods at 4, 16, and 20 weeks after discharge. Results: The ratio of males to females was 2.3 : 1, and the mean age was $56.3{pm}10.2$ years. The numbers of subtotal gastrectomies and total gastrectomies were 69 and 21, respectively. Fourteen (15.6%) patients dropped, of whom 5 belonged to the case group. Of the remaining 76 patients, those in the case group had higher levels of serum albumin (P=0.046). For patients who underwent subtotal gastrectomy (n=57), the case group had higher level of serum albumin (P=0.049). Conclusion: This double blind study showed that oral Saccharomyces boulardii therapy could improve the postoperative nutrition of gastrectomized patients because gastrectomized patients with oral Saccharomyces boulardii therapy had higher levels of serum albumin than the control group.