Hospice utilization metrics are essential for any serious effort to improve end-of-life care in oncology. However, oncologists do not routinely receive these personalized reports. We evaluated whether a behavioral science intervention, using peer comparisons coupled with social norms, was associated with improvements in hospice use. Oncologists at two academic practices of Johns Hopkins Medicine were randomly assigned to receive a peer comparison report by e-mail displaying individual hospice utilization metrics compared with top-performing peers or to receive no report. The data accrued for the intervention represented hospice utilization for the previous calendar year. The intervention period was from June 1, 2020, to December 30, 2020, and included oncologists from both the solid and hematologic malignancies programs. The primary outcome was the proportion of patients between groups with short hospice length of stay (LOS; defined as ≤ 7 days) after 6 months. Secondary outcomes included hospice referral rate, enrollment rate, and median LOS. Forty-seven oncologists participated. The percent of patients with a short hospice stay in the intervention group was lower (17.4%) compared with patients treated by physicians in the usual care group (46.3%, difference = 21.8%; 95% CI, 16.0 to 41.6; P < .001). Receipt of peer comparisons was associated with a greater likelihood of enrolling in hospice (73.7% v 42.8%; difference = 31.1%; 95% CI, 20.4 to 41.7; P < .001) and a longer hospice LOS (37.2 v 18.3 days; difference = 17.2; 95% CI, 8.8 to 25.7 days; P < .001). Peer comparisons improved hospice utilization metrics among a group of academic oncologists. Behavioral science offers one pragmatic strategy to overcome suboptimal oncologist decision-making biases related to hospice use.