The objective of this study was to assess the psychometric properties of the French version of the Supportive Care Needs Survey for Partners and Caregivers (SCNS-P&C-F). The SCNS-P&C-F, the Hospital Anxiety and Depression Scale (HADS) and the CareGiver Oncology Quality of Life questionnaire (CarGOQoL) were completed by 327 caregivers at the baseline. The SCNS-P&C-F was completed a second time by 121 participants within 30 days. Four factors were retained with a good explanation of variance (82.65%) and acceptable internal consistencies (α: 0.70 to 0.94): 1) Health Care Service and Information Needs, 2) Emotional and Psychological Needs, 3) Work and Social Security Needs and 4) Communication and Family Support Needs. Overall, convergent and divergent validities were confirmed. The caregiver's gender, age, professional status and level of anxiety and depression, as well as the type of relationship with the patient and cancer, showed an effect on some caregivers’ unmet supportive care needs. Lastly, the test–retest reliability was acceptable (> 0.70), except for the communication and family support dimension. The scale is appropriate for clinical and research use (e.g. good reliability and validity).