64 patients with knee osteoarthritis were included in this randomized trial comparing bath therapy plus 2 weeks of peloid therapy (n=32) or peloid therapy applied over an impermeable stretch film. Outcomes of interest included pain, patient global assessment and physician global assessment on a Visual Analog Scale (VAS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and pro-inflammatory markers (IL-1b; IGF-1; TNF-alpha). Clinical outcomes were assessed post-treatment, 3 months post-treatment and 6 months post-treatment, while laboratory results were assessed at 6 months post-treatment. Results revealed significantly better WOMAC pain and stiffness scores at 6 months in the peloid therapy group. IGF-1 levels were significantly lower in the control group after treatment, but were not different at 6 months. Due to a TNF-alpha kit failure, samples were not able to be tested.