Family caregivers have become increasingly responsible for providing home care for cancer patients. Research has documented the distress of family caregivers; however, little has been done to evaluate the broader impact of caregiving on quality of life (QoL). The objectives of this study were to evaluate the reliability and validity of the Caregiver Quality of Life Index-Cancer (CQOLC), a new self-report instrument. Two hundred and sixty-three family caregivers of patients with lung, breast or prostate neoplasms participated. Test-retest reliability was 0.95 and internal consistency was 0.91. As expected, there were moderate correlations with overall mental health (r = 0.64), emotional distress (r = -0.50 to -0.52), burden (r = -0.65) and patient's performance status (r = -0.47) and low correlations with overall physical health (r = 0.13), social support (r = 0.22) and social desirability (r = 0.08). These results show that increased overall mental health is associated with better QoL, while more emotional distress and worsening patient performance status are associated with poorer QoL. Thus, the CQOLC appears to possess adequate validity, test-retest reliability and internal consistency. Future directions include further evaluation of sensitivity to change and factor analysis to determine the principal health-related QoL domains evaluated by the CQOLC.