This study analyzes the association between center usage rates and the rates of nonadmitted visits to emergency departments (EDs) for poisoning.With a log-normal regression model, we analyzed the association between the number of human exposure calls per hospitalized poisoning patient and the number of nonhospitalized ED visits. The data were from 14 states at county level.A 1% higher poison control center (PCC) human exposure call rate for unintentional poisoning is associated, but not necessarily causally, with a 0.18% lower ED visit rate (P < .0001). If the observed association is causative, 15.5 PCC human poison exposure calls prevent one nonadmitted ED visit, yielding a $205 net cost saving and a benefit-cost ratio of 1.4. The savings ignore any reduction in hospital admissions.Increased PCC exposure calls appear to be associated with reduced ED use for unintentional poisoning and appear to reduce net medical spending.