Objective: To verify the association between the level of comfort of the caregiver and socio-demographic variables related to caregiving, and the patient's functional status and symptoms.; Method: Cross-sectional study with non-probabilistic intentional sample. The instruments Palliative Performance Scale (score 0 to 100%), Edmonton Symptom Assessment Scale (symptom scores from zero to ten) and Holistic Comfort Questionnaire (total score ranging from 49 to 294 and mean score from 1 to 6) were used. The relationship between comfort scores and independent variables was calculated by multiple linear regression.; Results: Fifty informal caregivers participated in the study - 80% were female, 32% were 60 years old or older, 36% were children of the patient, 58% had paid work and 60% did not have help in the care. The mean overall comfort was 4.52 points. A better functional status of the patients was associated with higher levels of comfort of the caregivers. Older caregivers who received helped in the care activities presented higher comfort scores.; Conclusion: The level of comfort of caregivers of cancer patients receiving palliative care was associated with socio-demographic variables and patients' functional status and symptoms.