Reports of spontaneous rupture of a craniopharyngioma cyst are extremely rare. Five cases of spontaneous rupture of a craniopharyngioma cysts are reported. Clinical symptoms included chemical meningitis in three patients, alleviation of headache in one, and improvement in a visual disturbance in one. Reduction in cyst size was confirmed by computed tomography or magnetic resonance imaging in three of five patients, and the histopathological diagnosis was confirmed histologically in four patients. Cerebrospinal fluid findings were abnormal in the three patients with chemical meningitis. Spontaneous rupture of craniopharyngioma cysts tended to occur more frequently in adult males. Computed tomography and magnetic resonance imaging were useful in diagnosing cyst rupture, and cerebrospinal fluid findings, especially the presence of cholesterol crystals and an elevated cholesterol concentration, are suggestive, even when no reduction in cyst size is observed radiologically.