Mass hysteria is characterized by sudden symptoms based on autonomic imbalance such as hyperventilation and syncope that generally occur in a group such as female junior or senior high school students. Six young female inpatients (ranging in age from 17 to 32 years) in our psychosomatic ward developed in suvccession symptoms such as loss of consciousness persisting for several minutes to several days and atonic seizures. There are few reports on seizures occurring in many patients during a short period of time in the ward. Analysis of the pathological state in the 6 patients revealed only mutual consciousness, a relationship specific to females, but no serious conflict. We assume that such mass hysteria may frequently occur as a general phenomenon in the future.