Purpose To determine the effect of early versus delayed initiation of a palliative care intervention for family caregivers (CGs) of patients with advanced cancer. Patients and Methods Between October 2010 and March 2013, CGs of patients with advanced cancer were randomly assigned to receive three structured weekly telephone coaching sessions, monthly follow-up, and a bereavement call either early after enrollment or 3 months later. CGs of patients with advanced cancer were recruited from a National Cancer Institute cancer center, a Veterans Administration Medical Center, and two community outreach clinics. Outcomes were quality of life (QOL), depression, and burden (objective, stress, and demand). Results A total of 122 CGs (early, n = 61; delayed, n = 61) of 207 patients participated; average age was 60 years, and most were female (78.7%) and white (92.6%). Between-group differences in depression scores from enrollment to 3 months (before delayed group started intervention) favored the early group (mean difference, −3.4; SE, 1.5; d = −.32; P = .02). There were no differences in QOL (mean difference, −2; SE, 2.3; d = −.13; P = .39) or burden (objective: mean difference, 0.3; SE, .7; d = .09; P = .64; stress: mean difference, −.5; SE, .5; d = −.2; P = .29; demand: mean difference, 0; SE, .7; d = −.01; P = .97). In decedents' CGs, a terminal decline analysis indicated between-group differences favoring the early group for depression (mean difference, −3.8; SE, 1.5; d = −.39; P = .02) and stress burden (mean difference, −1.1; SE, .4; d = −.44; P = .01) but not for QOL (mean difference, −4.9; SE, 2.6; d = −.3; P = .07), objective burden (mean difference, −.6; SE, .6; d = −.18; P = .27), or demand burden (mean difference, −.7; SE, .6; d = −.23; P = .22). Conclusion Early-group CGs had lower depression scores at 3 months and lower depression and stress burden in the terminal decline analysis. Palliative care for CGs should be initiated as early as possible to maximize benefits.