Intra-articular viscosupplementation with hyaluronic acid has become an increasingly accepted therapeutic alternative in the symptomatic management of osteoarthritis. Basic science research has documented numerous potential actions of exogenous hyaluronic acid upon the diseased joint. A substantial aggregate of clinical data suggests that viscosupplementation is clinically safe and suggests some therapeutic efficacy with regard to pain relief. However, a robust placebo effect and industry bias have obscured these outcomes considerably. Although recent attention has focused on the disease-modifying potential of this treatment option, definitive evidence is lacking. This paper will review the development, experience, indications, and clinical outcomes of viscosupplementation therapy in patients with osteoarthritis.