The origin and frequency of alarm soundings in a general purpose intensive therapy unit were recorded by the nursing staff for 3 weeks. Only eight out of a total of 1455 soundings indicated potentially life threatening problems. There were many false alarms from the monitoring system and the infusion rate pump. The overall frequency of soundings varied little by day or night. There is a need for a graded system of alarms to reflect the priority of the disturbance detected.