Clinical experience has shown an increase of behavioural and mood symptoms, especially in the areas of aggressiveness, sexuality and obsessiveness, during the late stages of ALS. The lack of conclusive data concerning these symptoms prompted us to assess the psychological aspects of ALS patients in advanced stages of the disease. Moreover, we evaluated the personality of their caregivers in order to analyse the relationship between the pair. For these purposes, we studied 10 patients with ALS in late stages (tracheostomized for 36 months) and their caregivers using a questionnaire specifically elaborated for patients' communication limits. To assess the state of anxiety and depression of both patients and caregivers, we used the Hospital Anxiety and Depression Scale (HADS). To investigate caregivers' personality, we administered the Big Five Questionnaire (BFQ). Data showed a trend of aggression and high level of obsessiveness in ALS patients, associated with several clinical characteristics. High levels of anxiety emerged in both patients and caregivers. Regarding BFQ, caregivers obtained higher scores in the dimension of Conscientiousness and very low scores in Extraversion and Emotional Stability. In conclusion, the study showed a potential and considerable effect of the long duration of ALS on patients' personality and caregivers' distress.