In most European countries, balneotherapy and spa therapy are widely prescribed by physicians and preferred by European citizens for the treatment of musculoskeletal problems including chronic low back pain (LBP). We aimed to review and evaluate the recent evidence on the effectiveness of balneotherapy and spa therapy for patients with LBP. We comprehensively searched data bases for randomized controlled trials (RCTs) published in English between July 2005 and December 2013. We identified all trials testing balneotherapy or spa therapy for LBP that reported that the sequence of allocation was randomized. We finally included total of eight RCTs: two on balneotherapy and six on spa therapy. All reviewed trials reported that balneotherapy was superior in long term to tap water therapy in relieving pain and improving function and that spa therapy combining balneotherapy with mud pack therapy and/or exercise therapy, physiotherapy, and/or education was effective in the management of low back pain and superior or equally effective to the control treatments in short and long terms. We used Jadad scale to grade the methodological quality. Only three out of total eight had a score of above 3 indicating the good quality. The data from the RCTs indicates that overall evidence on effectiveness of balneotherapy and spa therapy in LBP is encouraging and reflects the consistency of previous evidence. However, the overall quality of trials is generally low. Better quality RCTs (well designed, conducted, and reported) are needed testing short- and long-term effects for relieving chronic back pain and proving broader beneficial effects.