We evaluated the Lund-Manchester research criteria (LMRC) for frontotemporal dementia (FTD). With single-photon emission CT, we diagnosed 30 patients with FTD. These patients were compared with 30 with a research diagnosis of Alzheimer's disease (AD). We scored every patient on each LMRC item and compared the two groups. A discriminant function showed that loss of personal awareness, hyperorality, stereotyped and perseverative behavior, progressive reduction of speech, and preserved spatial orientation differentiated 100% of FTD and AD subjects. Items relating to affect and physical findings were not different in FTD versus AD. Loss of personal awareness, eating, perseverative behavior, and reduction of speech are the LMRC items that most clearly differentiate FTD from AD.