The usefulness as one of the tools for self-medication of oral rehydration therapy (ORT), recommended as a safe and effective therapy for mild to moderate dehydration, was surveyed by questionnaire for pharmacists in community pharmacies. ORT products were sold in 112 pharmacies (61%), and the common product was OS-1^®. Approximately 50% of sellers answered that they had no particular difficulty in explaining ORT. Percentage to answer “hard to describe” is significantly higher in pharmacists who believe there is a need to consider underlying health conditions of customers or patients when implementing ORT. Around 77% of pharmacists considered ORT to be useful in patients as a method of self-medication. A significant number of pharmacists selling ORT products depends on the consultation from customers or patients and provide advice to them confirming that ORT was useful. From these results, it was suggested that further information concerning ORT, such as its use in patients with chronic disorders or signs for completion, and the initiative of pharmacists to participate are necessary for spread the efficacy of ORT for self-medication in patients.