Aim: Two recommendations for hemodialysis in lithium poisoning, one from the Extracorporeal TReatments in Poisoning (EXTRIP) workgroup and a single center retrospective one (Paris), differ. We compared outcomes in lithium poisoning based on these criteria with a primary outcome of worsening neurological symptoms in patients where EXTRIP and Paris criteria were discordant. Methods: Poison center data were queried for lithium poisoned patients for whom hemodialysis was either recommended or performed. Patients were categorized according to EXTRIP and Paris criteria and excluded if the peak lithium concentration was <1.2 mmol/L or if neurological follow-up was unavailable. Comparative analyses were only performed when both criteria could be assessed. Results: 219 patients were analyzed. Paris criteria were applied in 70 and EXTRIP criteria in 178. 42 patients were excluded because Paris criteria could not be applied. When Paris and EXTRIP both supported hemodialysis, 50/57 (88%) of patients who received hemodialysis improved, as did all 3 who did not receive hemodialysis. When Paris and EXTRIP opposed hemodialysis, all non-dialyzed patients did well. Among the 86 patients for whom EXTRIP supported hemodialysis but Paris did not, 4/19 (21%) patients not dialyzed deteriorated (p=0.02; OR=8.7, 95%CI=1.5-51.8), one of whom died. All 8 patients for whom Paris criteria supported hemodialysis but EXTRIP did not were dialyzed and improved. Conclusion: When the EXTRIP and Paris criteria are discordant, EXTRIP criteria outperforms the Paris criteria at identifying potentially ill patients who might benefit from hemodialysis.