ObjectivesNursing home (NH) staff often report not having adequate dementia-specific knowledge to effectively care for these residents. Between 2011 and 2019, 9 states in the United States implemented dementia training requirements for NH staff. This study evaluated whether the state-mandated dementia training for NH staff was associated with improving resident outcomes. DesignCompared trends in antipsychotic medication before and after implementation of state training requirements to trends in states without requirements. Setting and ParticipantsNHs. MethodsData from Care Compare for NHs and LTCFocus were linked to state policy data. We excluded 14 states that had implemented training requirements before the start of the study period in 2011. We estimated difference-in-differences models that compared trends in antipsychotic medication use before and after implementation of training requirements in states that have newly implemented requirements to trends in states without requirements. We also investigated whether the impact of training was larger in states with more stringent training requirements (eg, specifying a minimum number of training hours) and in NHs with a special care unit for dementia and examined similar analyses for restraint use and falls. ResultsWe found that training requirements were associated with a 0.59–percentage point reduction (95% CI −0.91 to −0.27) in antipsychotics use. Effects were larger in NHs with a special care unit for dementia and in states that had stricter training requirements. We also found that training requirements were associated with a 0.17–percentage point reduction (95% CI −0.26 to −0.07) in restraint use measure and had no impact on falls. Conclusions and ImplicationsState requirements for NH staff dementia training were associated with a small, but significant, reduction in the use of antipsychotic medication and physical restraints.