Patient satisfaction is an important indicator of mental healthcare quality. The Client Satisfaction Questionnaire-8 (CSQ-8) is widely used, but its psychometric performance and contextual relevance have not been examined in humanitarian settings.

To assess the reliability and validity of the CSQ-8 in a sample of displaced and conflict-affected Syrian mental health and psychosocial support (MHPSS) service users.

Structured telephone interviews were conducted with Syrian MHPSS service users in North-West Syria. Psychometric analysis assessed the internal consistency and construct validity of the CSQ-8. Convergent validity with therapeutic alliance was examined using the Working Alliance Inventory Short Revised. Item comprehension and contextual relevance were examined using open-ended qualitative responses.

Among 337 participants, the CSQ-8 demonstrated strong internal consistency (ω = 0.92), but suboptimal model fit (comparative fit index 0.922; Tucker–Lewis index 0.890; root mean square error of approximation 0.132). Convergent validity with therapeutic alliance confirmed the importance of service user–practitioner relationships to satisfaction. Item 4 (‘Would you recommend the service?’) and item 8 (‘Would you return to the service?’) showed large ceiling effects and weaker psychometric properties. Qualitative data indicated responses to these items were shaped by community stigma, low expectations and a lack of alternative services, rather than satisfaction. A secondary analysis of the CSQ-4 showed good reliability (ω = 0.81) and improved model fit (comparative fit index 0.993; Tucker–Lewis index 0.980; root mean square error of approximation 0.065).

In this humanitarian setting, items about a willingness to recommend and intent to return to a service may lack conceptual validity and should be used cautiously. Shorter forms such as the CSQ-4 may be a useful alternative.