We performed a cross-sectional study aimed to address the quality of life (QoL) and putative associated variables in amyotrophic lateral sclerosis (ALS) patients and their respective caregivers, using both health-related (WHOQOL-BREF) and individual (SEIQoL-DW) QoL instruments. Further, we sought to investigate concordance within patient-caregiver pairs for ratings of respective QoL. Thirty-seven patient-caregiver pairs were included in the study. QoL was rated low by both patients and caregivers, and there was no significant difference between them on scores of overall QoL, even if caregivers showed higher scores on the physical and psychological WHOQOL-BREF domains compared to patients. No correlation could be found between QoL of both patients and caregivers and all the examined socio-demographic variables. Moreover, concordance between patients and respective caregivers was low for ratings of QoL, suggesting that their QoL is not necessarily interrelated, and that these couples do not actually represent a unique psychological entity. Interestingly, physical dysfunction, measured with the ALS-FRS, was not significantly correlated with caregivers' individual QoL scores. The most frequently nominated SEIQoL-DW cues were related to health (physical and psychological) and family for both patients and caregivers, and there was high agreement for the choice of areas important for subject's QoL. Interestingly, patients and caregivers who endorsed spirituality as a significant domain reported better QoL. Our study confirms that ALS has a negative impact on QoL in both patients and caregivers. However, caregivers who present lower QoL levels are not always those who have to look after the most physically or psychologically impaired patients. Major attention on QoL issues of both patients and caregivers, family status, and health perception, integrated with the medical evaluation, could lead to a better understanding of the problems related to the caregiving experience, and could help couples dealing with this life-threatening disease.