Background <p>Timely, individually tailored support for family caregivers of cancer patients is stressed, reinforcing the importance of implementing screening tools in clinical practice.</p> Aim <p>This study aims to evaluate the validity and reliability of the Swedish CancerSupportSource-Caregiver among 145 Swedish family caregivers of persons diagnosed with cancer.</p> Methods <p>We evaluated the validity and reliability of the Swedish CancerSupportSource-Caregiver among 145 Swedish family caregivers of persons diagnosed with cancer who responded to the Swedish CancerSupportSource-Caregiver, sociodemographic questions, and the Hospital Anxiety and Depression Scale. Psychometric analyses were performed using descriptive statistics and classical test theory to evaluate data quality, targeting, scaling assumptions, and internal validity. Construct validity was assessed through confirmatory factor analysis; criterion validity through concurrent validity; and reliability through internal consistency.</p> Result <p>Overall, in the sample, evaluations demonstrated generally satisfactory psychometric properties with respect to data quality, targeting, and scaling assumptions. The hypothesized five-domain model showed an acceptable fit to the data, although there were indices that it could be improved. Item loadings were generally high, supporting the proposed construct structure. Further, assessments of the criterion validity were satisfactory. However, the evaluations of internal validity and internal consistency indicated redundancy, mainly within the <i>emotional well-being</i> domain.</p> Conclusion <p>The Swedish CancerSupportSource-Caregiver demonstrated preliminary satisfactory abilities to screen for support needs and psychological distress among Swedish family caregivers of persons diagnosed with cancer. Further evaluations in larger samples, using Rasch measurement theory, could provide a deeper understanding of the functioning of items and response options.</p>