Trapeziometacarpal osteoarthritis predominantly affects middle-aged women. Most cases with rhizarthrosis can be managed successfully by conservative means. The purpose of this prospective study was to evaluate pain and tolerability of viscosupplementation therapy with hyaluronic acid (HA) for trapeziometacarpal osteoarthritis. Groups A and B consisted of eight patients each with Eaton stage 3 or 4 rhizarthrosis, who underwent one cycle of three injections of (one per week) 0.3 cm(3) sodium hyaluronate. The injections for group A were under fluoroscopy control, but fluoroscopy was not used in group B. Pain and tolerability of both groups A and B were measured and compared. The patients of the groups were also asked to evaluate the tolerability of the treatment. The results suggested that HA injection in the carpometacarpal joint is a tolerable procedure but the patients complained of pain and discomfort during the injections. The pain in group A was much greater than in group B. Viscosupplementation for the treatment of trapeziometacarpal osteoarthritis is a viable treatment option for stages 3 and 4 patients when they do not want to be operated on. It is a tolerable but not a painless procedure especially when it is done without fluoroscopy control. We recommend giving injections under fluoroscopy control.