This study enrolled 184 middle-aged and older women (95 Non-Hispanic White and 89 Hispanic/Latino) who provided in-home hands-on care to an elderly relative with Alzheimer's disease or another form of dementia. Within ethnic group they were randomly assigned to either a CBT-based small group intervention program called “Coping with Caregiving” (CWC) that taught a variety of cognitive and behavioral skills to reduce stress and depression, or to a minimal telephone based control condition (TSC). Intervention lasted about 4 months; one post-treatment assessment was completed 6 months after baseline by interviewers blind to the intervention condition. Interviews and interventions were conducted in English or Spanish by trained staff. Results indicated that those in the CWC (regardless of ethnicity) showed greater improvement from pre to post intervention than those in the TSC on measures of depressive symptoms, overall life stress, and caregiving-specific stress. In order to investigate if these changes may have been related to one proposed mechanism of change in CBT (skill utilization), a new measure was constructed. Change in frequency of use and perceived helpfulness of adaptive coping skills were assessed in all caregivers. Results indicated that caregivers in CWC reported greater frequency of use, and greater perceived helpfulness, of these skills at post intervention compared to caregivers in the TSC. Improvement measured by dependent measures was correlated with an increase in these indices for those in the CWC. Tests for mediation suggest that effective skill utilization may mediate the effect of treatment on outcome. Implications of these findings are discussed and recommendations provided for future research.