Introduction:The existing literature shows a significant impact of cancer on caregivers' quality of life (QoL) and divergent results according to associated factors. To better understand the experience of cancer patients' caregivers, the present study aimed at comparing caregivers’ QoL according to cancer care pathway and type of cancer, and at identifying the factors associated with their QoL. Methods:Caregivers were included in the study either during chemotherapy or follow-up to assess their QoL (CARGOQoL), unmet supportive care needs (SCNS–P&C), and anxiety and depression levels (HADS). CARGOQoL scores were then compared using ANOVA or Mann-Whitney non-parametric tests (objective 1). Based on univariate analyses, a multivariate analysis of covariance or linear regression model was performed for each CARGOQoL dimension (objective 2). Results:Among 583 participants (57.29% included during the follow-up phase), 523 completed the questionnaires. There was no effect of treatment phase and little effect of cancer site or disease stage on caregivers' QoL. Although significant factors associated with caregivers' QoL varied according to the dimensions assessed, the main associated factors were psychological experience (p < 0.05), satisfaction with the patient's care and supportive care needs (p < 0.01), and age of the patient or caregiver (p < 0.005). Conclusion:This study shows the necessity to support caregivers during both active treatment and follow-up. It highlights the crucial role of emotional distress, supportive care and age in caregivers' QoL, regardless of the patients’ oncological status.