Purpose To estimate the prevalence of sperm banking among adolescent males newly diagnosed with cancer and to identify factors associated with banking outcomes. Patients and Methods A prospective, single-group, observational study design was used to test the contribution of sociodemographic, medical, psychological/health belief, communication, and developmental factors to fertility preservation outcomes. At-risk adolescent males (N = 146; age 13.00 to 21.99 years; Tanner stage ≥ 3), their parents, and medical providers from eight leading pediatric oncology centers across the United States and Canada completed self-report questionnaires within 1 week of treatment initiation. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% CIs for specified banking outcomes (collection attempt v no attempt and successful completion of banking v no banking). Results Among adolescents (mean age, 16.49 years; standard deviation, 2.02 years), 53.4% (78 of 146) made a collection attempt, with 43.8% (64 of 146) successfully banking sperm (82.1% of attempters). The overall attempt model revealed adolescent consultation with a fertility specialist (OR, 29.96; 95% CI, 2.48 to 361.41; P = .007), parent recommendation to bank (OR, 12.30; 95% CI, 2.01 to 75.94; P = .007), and higher Tanner stage (OR, 5.42; 95% CI, 1.75 to 16.78; P = .003) were associated with an increased likelihood of a collection attempt. Adolescent history of masturbation (OR, 5.99; 95% CI, 1.25 to 28.50; P = .025), banking self-efficacy (OR, 1.23; 95% CI, 1.05 to 1.45; P = .012), and parent (OR, 4.62; 95% CI, 1.46 to 14.73; P = .010) or medical team (OR, 4.26; 95% CI, 1.45 to 12.43; P = .008) recommendation to bank were associated with increased likelihood of sperm banking completion. Conclusion Although findings suggest that banking is underutilized, modifiable adolescent, parent, and provider factors associated with banking outcomes were identified and should be targeted in future intervention efforts.