Rapid tranquillisation--giving a psychotropic to control behavioural disturbances--is common in medical practice, yet few surveys describe its use in psychiatric populations. Over five months, 102 incidents, involving 60 patients, were retrospectively surveyed. Patients most often involved were young white men. The commonest diagnosis was affective disorder (manic phase) (39%) followed by schizophrenia (33%). Fifteen patients were involved in 57% of the incidents. The majority of incidents involved injury to people or damage to property. The most frequently used drugs were diazepam and haloperidol, alone or in combination. Droperidol, chlorpromazine, sodium amytal and paraldehyde were rarely used. Diazepam alone or in combination with haloperidol delivered intravenously was most rapidly effective and was associated with greatest staff satisfaction. Serious side-effects were rare.