Wireless capsule endoscopy is a new diagnostic tool in which a disposable video capsule is swallowed by the patient. This examination enables visualization of the small intestine that is not within the reach of conventional upper and lower endoscopy. The best indications include an obscure source of gastrointestinal bleeding, Crohn's disease, and small intestinal tumors. The disadvantage that biopsy cannot be performed is compensated for by employing double-balloon endoscopy. In particular, this examination can identify the origin of bleeding and diagnose the underlying disease, leading to prompt surgical treatment with better results. In future, capsule endoscopy will become a necessary examination for diagnosing digestive tract disease.