Misasa Spa, located in Tottori Prefecture, was discovered in 1164, and it has been widely used for the management of rheumatic disorders, gastrointestinal diseases and so on. In 1914, Dr. R. ISHIZU measured radon contents in Misasa spring waters to be 142.14 Mache, and then Misasa Hot Springs, alkaline common salt springs, were also known as radioactive hot springs. In July, 1958, patients with rheumatic complaints who had balneotherapy at Misasa Branch Hospital of Okayama University, from January, 1955 to March, 1958, were reexamined. A questionnaire about the effectiveness of balneotherapy was sent to 149 patients and 98 answers were received. The results were as follows: 1. Spa treatment was effective in 100% of shoulder-hand syndrome and osteo-arthrosis of the knee, in 95% of degenerative spondylosis, in 93% of rheumatoid arthritis, in 80% of low back pain, in 67% of sciatica, etc. Generally speaking, balneotherapy was effectual in 78 of 98 patients with rheumatic disorders (81.2%). 2. The effectiveness of spa treatment came out in the course of thermal cure in 74% of 78 cases, and the others recognized the effects after spa treatment was finished. 3. The effect of spa therapy on the subjective complaints was notable in the cases which had a period of spa treatment over half a month. In the cases which had a period of spa treatment within 2 weeks, it is thought that the period is too short to reveal the efficacy of hot spring bathing. 4. It appeared that drinking of hot spring water had no remarkable effect on rheumatic complaints. 5. Forty-three per cent of the cases answered that their body conditions during this inquiry time became better than that at the beginning of the balneotherapy, and the remainders of the reexamined cases were under the trcatments with cortisone, vitamine, massage, acupuncture and so forth.