Ciprofloxacin and other fluoroquinolones are commonly used broad-spectrum antimicrobial agents for treating bacterial infections. This class of antibiotic drugs has uncommon adverse effects that include tendonitis, tendon ruptures, and other tendon abnormalities. We describe a patient with spontaneous bilateral complete Achilles tendon rupture after ciprofloxacin treatment. Surgical repair was performed successfully, and the patient completed physical rehabilitation without incident. Care should be exercised when selecting pharmaceutical agents to maintain a positive benefit-to-risk balance.