Purpose Decision making is one of the ways in which parents serve as stewards of their children with cancer, but barriers to informed decision making among parents of children with cancer have been identified. We sought to evaluate the extent to which parents feel satisfied with, or regretful of, decisions made for their child's cancer treatment and to identify factors associated with heightened regret. Methods We surveyed 346 parents of children with cancer within 12 weeks of their initial cancer treatment decision and the children's physicians at Dana-Farber Cancer Institute/Boston Children's Hospital and the Children's Hospital of Philadelphia. Our main outcome measure was heightened regret as measured by the Decisional Regret Scale. Results Sixteen percent of parents (N = 54) met our definition of heightened decisional regret. In a multivariable logistic regression model, race/ethnicity was associated with regret, with black (odds ratio [OR], 6.55; 95% CI, 2.30 to 18.7), Hispanic (OR, 2.15; 95% CI, .69 to 6.65), and other race parents (OR, 4.68; 95% CI, 1.58 to 13.8) at increased risk for regret relative to whites ( P = .001 across all categories). In contrast, parents who reported receiving high-quality information (OR, .45; 95% CI, .23 to .91; P = .03) and detailed prognostic information (OR, .48; 95% CI, .24 to .96; P = .04), who trusted the oncologist completely (OR, .32; 95% CI, .17 to .63; P = .001), and who held their ideal role in decision making (OR, .49; 95% CI, .25 to .95; P = .04) were less likely to experience regret. Conclusion Although many parents are satisfied with decisions made for their children with cancer, racial and ethnic minority parents are at heightened risk for regret. Clinicians may be able to reduce this risk by providing high-quality information, including prognostic information, involving parents in decision making in the ways they wish, and serving as trusted providers.