Posttraumatic growth (PTG) after cancer can minimize the emotional impact of disease and treatment; however, the facilitators of PTG, including support seeking, are unclear. The authors examined the role of support seeking on PTG among 604 breast cancer survivors ages 40 to 64 from the Health Eating, Activity, and Lifestyle (HEAL) Study. Multivariable linear regression was used to examine predictors of support seeking (participation in support groups and confiding in health care providers) as well as the relationship between support seeking and PTG. Support program participation was moderate (61.1%) compared to the high rates of confiding in health professionals (88.6%), and African Americans were less likely to report participating than non-Hispanic Whites (odds ratio = .14, confidence intervals [0.08, 0.23]). The mean (SD) PTG score was 48.8 (27.4) (range 0-105). Support program participation (β = 10.4) and confiding in health care providers (β = 12.9) were associated (p < .001) with higher PTG. In analyses stratified by race/ethnicity, PTG was significantly higher in non-Hispanic Whites and African American support program participants (p < .01), but not significantly higher in Hispanics/Latinas. Confiding in a health care provider was only associated with PTG for non-Hispanic Whites (p = .02). Support program experiences and patient-provider encounters should be examined to determine which attributes facilitate PTG in diverse populations.