Background: HIV+ adults have reduced quality of life due to disease-related morbidity and adverse events related to standard medical therapy. Constitutional hydrotherapy is a traditional treatment reported to improve immune function and general well-being. Clinical research on hydrotherapy is needed. Objective: To evaluate the short-term tolerability, safety and clinical effects of twice-weekly constitutional hydrotherapy treatments over a 6-week period in HIV+ adults. Methods: The present study was an eight-week pilot clinical trial of fifteen HIV+ adults receiving twelve constitutional hydrotherapy treatments each over 6 weeks in an academic, Naturopathic medical clinic. Outcome measures: Retention in the trial, adverse events, CD4+ count, viral load, and clinical chemistries, including TNF-alpha levels, erythrocyte sedimentation rate, and C-reactive protein. Other measures included anthropometrics and quality of life as measured by the RAND 36-Item Short Form Survey (SF36). Two-sided, paired t-tests for homogeneity were applied to the difference in outcome variables between baseline and exit interviews. Results: 12 of 15 participants completed the study per protocol. Treatments were well-tolerated and without any reported "Severe" side effects. No statistically significant adverse changes were observed in hematologic or inflammatory biomarkers, or anthropometric measures. There were no significant changes in CD4+ count or viral load. Changes in clinical chemistries were non-significant, except for a reduction on sodium concentration (139.6 mmol/L +/- 1.7 to 137.5 +/- 1.8; p = 0.005). A non-significant decrease in mean hs-CRP was observed (7.5 mg/L, +/- 14.2 to 1.7 mg/L, +/- 1.4, p = 0.21) with an absolute decrease in hs-CRP in each of the three participants with elevated hs-CRP levels at baseline. A nonsignificant reduction in systolic blood pressure (SBP) was observed (mean change -7.7 mmHg, p = 0.22) with 58% of participants experiencing reductions in SBP. Mean percent body fat decreased significantly (22.3 +/- 4.0 to 20.7 +/- 5.2, p < 0.0001). In addition, a statistically significant increase in mean Energy/Fatigue score was observed (17.8 to 20.3, p = 0.03) using the RAND-36 Short Form. Trends for improved Physical Functioning and Pain scores were of borderline significance (87.9 to 94.1, p = 0.10 and 15 to 16.5, p = 0.08 respectively). All remaining domains, including General Health, were without trend for change. Conclusions: This clinical pilot study suggests constitutional hydrotherapy can be feasibly and safely administered to HIV+ adults, including those receiving HAART, without serious short-term adverse effects. Small, but significant, increases in clinical measures, physical functioning and quality of life were observed. (C) 2017 Published by Elsevier Ltd.