Objective: Leejung-tang (Rechu-to in Japanese) is a traditional Korean herbal formula used for treatment of gastrointestinal disorders such as vomiting, stomach pain, chronic gastritis and gastrointestinal ulceration. The present study was carried out to investigate the potential acute toxicity of Leejung-tang water extract (LJT) by a single oral dose in Crl:CD (SD) rats in compliance with current guidelines. Methods: In the preliminary study, there were no adverse effects such as death, clinical signs, and body weight changes at dose levels of 500, 1000, and 2000 mg/kg/day body weight. Based on the results, a dose of 2000 mg/kg was selected as the toxicological limited dose. LJT was administered once by gavage to male and female rats at dose levels of 0 and 2000 mg/kg bodyweight. During the study period, mortalities, clinical findings, and body weight changes were observed for 14 days following the administration. On day 14 after the treatment, the animals were sacrificed by carbon dioxide overdose and complete gross postmortem examinations were performed. Results: In present study, no treatment-related deaths were observed. There were no adverse effects on clinical signs and body weight changes. In addition, there were no observed gross findings in all groups except for a kidney cyst in the 2000 mg/kg/day female group. Conclusion: The results indicated that LJT did not induce toxic effects at a dose level up to 2000 mg/kg in rats and its median lethal dose ($LD_{50}$) was considered to be over 2000 mg/kg/day body weight for both genders.