Suicide is a serious public health problem. Recognizing this, many communities have initiated antisuicide programs. This communication describes the rationale, operation, and experiences of a suicide-prevention telephone service which functions nights, weekends, and holidays to supplement an active daytime, crisis-oriented, brieftherapy clinic. During the first year, 1,607 calls were received. Approximately two thirds of the patients concerned were women. Wednesday was the busiest night. Nearly one fifth of the calls involved persons with high suicide potentiality. A suicide attempt had been made recently by 22%. There was a history of one or more previous psychiatric contacts for 45% of the patients. Acute depressive reaction was the most frequent diagnosis.