Introduction:
Low back pain is the most common musculoskeletal disorder. Hydrotherapy may assist a variety of pathological conditions, including low back pain. The purpose of the study is to examine the effectiveness of hydrotherapy in chronic low back pain.

Methods:
A comprehensive search of PubMed, MEdLiNE, Elsevier, and Google Scholar was conducted for randomized controlled trials published in the period of 2009–2019 that investigated therapeutic aquatic exercise for low back pain. Particularly, the examined variables were (a) pain, (b) disability, (c) quality of life, (d) functional ability and physical condition, (e) psychological state, (f) body composition, (h) vertebral height and nerve compression symptoms, and (i) kinesiophobia. PEdro scale, which measures the methodological quality of randomized studies, was used.

Results:
overall, 13 studies were included and the results showed a relief of pain and disability and an improvement of quality of life and psychological state after hydrotherapy. in accordance with the PEdro scale, the average methodological quality of the studies was 5.08/10.

Conclusions:
Hydrotherapy may have a positive effect in patients with chronic low back pain. Further high-quality studies on a larger scale are required to confirm these results.