Poisonings and toxic exposures are a frequent cause of preventable morbidity in children requiring emergency care. Ingestions and toxic substance exposures were studied in two prospective cohorts in Hawaii to examine the epidemiology of these events in this community in order to assess the effectiveness of current poison prevention practices and to identify additional measures to further prevent and reduce morbidity and mortality. During a 12-month period ending on 11/30/88, data were collected on 286 pediatric patients visiting a pediatric ED with an ingestion or a toxic substance exposure. Most of the younger children were males with unintentional incidents. Most of the adolescents were females with intentional ingestions. Syrup of ipecac was given in 16% of the patients. When given at home, ipecac was given an average of 1.3 hours after an ingestion. Activated charcoal was given to 32% of the patients. During a 13-month period ending 1/31/90, 14,408 phone calls to the Hawaii Poison Center were analyzed. Twenty-six percent of the callers had ipecac at home. Sixty-eight percent of callers with acute ingestions claimed to have called within 30 minutes of the ingestion, and 77% claimed to have called within 60 minutes of the ingestion. Of those calling within 60 minutes, 36% had ipecac at home. Although ipecac is widely recommended as a pre-hospital intervention, it use is limited owing to unavailability in the home and the short period of time during which it must be given. Since the dispensing of pharmaceuticals in limited quantities and in childproof containers began, it appears that other measures to further reduce morbidity and mortality owing to poisonings have had less additional effect. It appears that serious morbidity and mortality from poisonings in this cohort were uncommon.