Two patients with giggle incontinence were examined. One patient was shown to have a convulsive disorder as well as giggle incontinence. Anticonvulsant therapy with phenytoin sodium prevented the incontinence. In the second case, a cystometrogram performed while the patient was laughing demonstrated bladder tetany with off-scale (>100 cm H2O) high pressure, in contrast to lower transient increases associated with "stress maneuvers"—Valsalva maneuver, coughing, and "forced" laughter. These two cases provide new insights into the pathophysiology of giggle incontinence.