Introduction: Tetanus is a highly fatal infection that causes tonic convulsions. Although magnesium sulfate may be effective as a treatment option for myopathic symptoms, there is little knowledge regarding its use. Therefore, this study assessed the use of magnesium sulfate for patients with tetanus requiring critical care management.Methods: Using multiple mailing lists of registered physicians in Japan, a questionnaire survey was conducted on the conditions during which magnesium sulfate was used for patients with tetanus requiring critical care management. An internet questionnaire form service was utilized.Results: The number of targets in this study was 24,266 and responses were received from 604 physicians, 252 of whom treated patients with tetanus requiring critical care management. In total, 126 of the above physicians used magnesium sulfate for tetanus.Conclusion: Magnesium sulfate was used for a substantial number of patients with tetanus requiring critical care management. To establish the utility of magnesium sulfate as a tetanus treatment option, further evidence is required.