Fluoroquinolones are relatively safe, effective antibiotics. As their use becomes more frequent, so will the adverse side effects. I highlight a rare but debilitating adverse reaction-fluoroquinolone-induced tendinopathy. Case reports and letters from 1987 to 1998 were identified by using Grateful Med and PubMed Internet accesses to the National Library of Medicine. Articles were reviewed for clinical practicality. There are few articles on fluoroquinolone-induced tendinopathy in the US literature targeting primary care physicians. This entity has been described in many case reports, but little has been done to isolate the causative agents. Incidence of this side effect is difficult to estimate, since no prospective studies are available for review or calculation of risk. Fluoroquinolone-induced tendinopathy appears more commonly in tendons under high stress. The cause is probably multifactorial. Risk factors for the development of fluoroquinolone-induced tendinopathy are age, renal failure, corticosteroid use, and previous tendinopathy from fluoroquinolones.