The aim of this study was to evaluate whether balneotherapy might be effective in patients with chronic pelvic pain (CPP) in the short term. This was an open and prospective pilot study. The balneotherapy programme was performed in a spa resort located in Wando Island, Republic of Korea from August 26 2018 to September 1 2018. It consisted of 10 heated seawater baths (38 °C, 20 minutes) and 10 mud-pack applications (40 °C, 10 minutes) for five days. Sixteen patients were enrolled. Upon analysing responses from a patient questionnaire, we found improvement in parameters such as pain, bladder irrigation symptoms and quality of life after balneotherapy. Inflammatory marker IL-1 and TNF-α was significantly decreased after treatment compared to baseline. There were no adverse events during treatment. Our data suggest that five-day balneotherapy can be beneficial for patients with CPP in the short term. Impact statement What is already known on this subject? The majority of articles in the field of balneotherapy discuss the treatment of rheumatic or dermatological disease. However, data on the effectiveness of balneotherapy for chronic pelvic pain are very limited. What the results of this study add? Our study suggests that balneotherapy can be beneficial for patients with CPP in the short-term. The duration of balneotherapy was five days, which is shorter than that of the European studies. Intuitively, it may be doubtful whether short-term therapy has any practical effect. As most people living in Korea have a vacation period of about one week each in summer and winter, the choice of a five-day programme in our study reflects the reality of vacation schedules. What the implications are of these findings for clinical practice and/or further research? Further studies are necessary to demonstrate the persistence of these benefits on the long term, as well as their existence in appropriate control group and different duration of treatment.