Evaluating the cognitive and behavioral features in amyotrophic lateral sclerosis (ALS) patients is important for therapy and care. Fifty-seven ALS, 5 ALS with the behavioral variant of frontotemporal dementia (FTD) (ALS-FTD), 12 FTD patients, and 35 control subjects were evaluated by 10 different tests for cognitive and behavioral (mini-mental state examination (MMSE), Hasegawa dementia rating scale - revised (HDS-R), frontal assessment battery (FAB), Montreal cognitive assessment (MoCA), ALS-frontotemporal dementia-Questionnaire (ALS-FTD-Q), and anosognosia scale), affective (depression, apathy, and behavioral and psychological symptoms of dementia (BPSD)), and activities of daily living (ADL) assessments. The motor functions of ALS patients were evaluated by ALS functional rating scale - revised (ALSFRS-R) and modified Norris scale. ALS-FTD-Q scores showed intermediate behavioral disturbances of ALS patients between ALS-FTD and FTD patients and control subjects, but FAB, MoCA, and anosognosia scales did not. Both FAB and MoCA scores were significantly correlated with MMSE and HDS-R in ALS patients, but ALS-FTD-Q was not. ALS-FTD-Q score was significantly correlated with ALSFRS-R, apathy, BPSD, and ADL scores in ALS patients. Thus, in ALS patients, both FAB and MoCA tests were useful to assess frontal cognitive impairments, while ALS-FTD-Q was useful to detect mild behavioral and affective disturbances.