A 1998 survey of all 73 US poison centers, including 52 certified centers and 21 noncertified centers, is presented. Despite a continued decline of the number of poison centers operating in the US, the volume of calls has steadily increased. In 1997 these centers handled 3.65 million telephone consultations, including 2,475,010 human poison exposure cases, 134,646 animal poison exposures, and 1,036,148 information calls. Nearly the entire US population had access to a poison center (99.9%), although only 78.5% of the US population was served by a certified center. Certified poison centers handled 83.6% of human poison exposure cases reported to US poison centers. Calls to certified centers were twice as likely to be handled by staff who were certified as specialists in poison information. On average, poison center utilization was 9.2 human exposure consultations/1,000 population. Total national poison center expenses approached $81 million. The average cost/human exposure case was $33.30 in certified centers, a substantial savings when compared with the alternative of emergency department management. State governments provided the single largest source of funding. Poison center funding remains unstable, with 41% of centers reporting a possible or definite budget reduction anticipated in the next budget year. In the past 5 y, 47.9% of centers faced threat of closure. Center certification and increased public education activity, especially the distribution of poison prevention materials and number of media contacts, were associated with greater utilization of the poison center in the region served.