BACKGROUND: Previous studies have shown an association between the rates of suicide employing certain types of medications and the availability of those drugs. During recent years, prescription patterns of psychoactive drugs commonly used in suicides have undergone some major changes. This study examines whether altered prescription patterns are associated with changes in the rates of drug-related suicides in the elderly. METHODS: An ecological study was performed, in which rates of suicide by drug poisoning were related to prescription sales of different psychotropic drugs, derived from the National Prescription Survey (1987-1996). RESULTS: Benzodiazepines were the dominant drug type used by elderly persons who committed suicide by drug poisoning. Rates of suicide using benzodiazepines increased despite decreasing prescription sales. Decreasing tricyclic antidepressant sales and increasing SSRI (selective serotonin reuptake inhibitors) sales were paralleled by decreasing rates of suicides employing antidepressants. The fatality ratio (FR) decreased for the antidepressant group, increased for benzodiazepines and remained more or less unchanged for analgesics among the elderly during the study period. CONCLUSIONS: Rates of suicide using benzodiazepines increased in the elderly despite decreasing prescription sales. Benzodiazepines should be prescribed restrictively to this age group.