Objectives: This study investigated the mediating role of pain behaviours in the association between pain catastrophising and pain intensity and explored the moderating role of family caregivers' responses to pain in the link between pain behaviours and pain intensity.; Methods: The sample consisted of 154 chronic pain patients and their family caregivers. Patients completed questionnaires regarding pain intensity, pain catastrophising, pain behaviours and their caregivers' responses to their pain. Family caregivers reported their responses to the patients' pain.; Results: Pain catastrophising was associated with pain intensity (r = 0.37) and pain behaviours partly mediated this association. The positive association between pain behaviours and pain intensity was significant only if patients reported that their family caregivers showed high levels of solicitous (effect = .49) and distracting responses (effect = .58), and if caregivers reported to show high levels of solicitous responses (effect = .51). No support was found for negative responses as a moderator neither based on patients' perception of negative responses nor based on caregivers' perception of negative responses.; Conclusions: The findings are in line with the idea that family caregivers' solicitous and distracting responses convey to patients that their condition is serious, which may reinforce patients' pain and pain behaviours, especially in those who catastrophise.