Musculoskeletal disorders including arthralgia and myalgia are adverse effect common to all fluoroquinolones. We report a case of spontaneous rupture of the patellar ligament in a 37-year-old man participating in leisure sports which occurred one month after a three-week course of Ciprofloxacine(R). Several cases of tendon ruptures have been reported in the literature, including the patellar tendon. Unusual features in our case were the one-month delay before tendon rupture and the absence of inaugural signs. We reviewed the pathophysiological mechanisms leading to fluoroquinolone-related tendon rupture as well as the risk factors and discussed proper management. Care must be taken when prescribing fluoroquinolones for patients at risk. Close follow-up is most important.