Background: Dementia with Lewy bodies (DLB) and Creutzfeldt-Jakob disease (CJD) share clinical features like cognitive decline, motor disturbances en psychiatric symptoms. Overlapping symptoms may cause physicians to mistake DLB for CJD. Methods: Clinical data of 12 patients with autopsy-confirmed DLB who had been clinically suspected to suffer from CJD were analysed to investigate possible clinical features which led to misdiagnosis. Results: There was an association in time between administering neuroleptics and rapid clinical deterioration in 8 out of 9 patients. Conclusion: It is suggested that the neuroleptic sensitivity in LBD fuelled the misdiagnosis of CJD in the presented series. Diagnostic confusion between CJD and DLB may have important clinical consequences and may lead to treatment restrictions.