Background: Delays in pregnancy exacerbate infertility. Thus, trainees are forced to make complex family planning decisions while juggling all aspects of training. In addition to a lack of parental leave and financial constraints, trainees are often concerned with the perceptions of leave and parenthood. Two single specialty surveys found that most program directors (PDs) felt parenthood negatively impacted trainee performance, disproportionately for women. We aim to understand PD and trainee perspectives of parental leave and parenthood in oncologic trainees. Methods: Contact information for PDs in oncologic specialties was gathered from FRIEDA. Surveys were distributed to all eligible PDs with a request to forward a parallel survey to their trainees. Social media links for both surveys were shared on Twitter. Tests of association for descriptive analyses included Fisher's exact test, Chi-square test, or the Mantel-Haenszel Chi-Square test, as appropriate. All computations were performed using SAS version 9.4. Results: 195 PDs and 286 trainees completed the survey with 49% and 56% female and 89% and 41% parent respondents, respectively. Per PDs, 73% of programs have a maternity leave policy, 48% have a paternity leave policy, and 5% have a fertility services policy. PDs and non-parent trainees (NPTs) rated the negative impact of parenthood on overall education (p < 0.001 for PDs, p < 0.001 for NPTs) and academic productivity (p < 0.001 for PDs, p < 0.001 for NPTs) as higher for women trainees than men trainees. PDs and NPTs also rated the burden of parental leave on co-trainees as greater for women trainees as compared to men trainees (p < 0.001 for PDs, p < 0.001 for NPTs). Among PDs, no significant differences by gender or specialty were found in advising for or against parenthood in training, but PDs in surgical specialties reported providing less support for trainees starting a family (p < 0.001) and trainees in surgical specialties reported being less supported (p < 0.001). Women trainees were more likely than men trainees to indicate that they would have started a family sooner if not in medicine (p < 0.001). 89% of parent trainees would choose to have children in training again, and 84% would recommend parenthood in training. Conclusions: Although many programs have parental leave policies, a substantial number continue to lack them. Concerns about negative perceptions of parenthood by trainees are valid, particularly for women who are significantly more likely to be seen as having their education and academic productivity impacted by parenthood. In addition, specialty choice impacts the support given to trainees as they start families. Despite these barriers, the vast majority of parent trainees would still choose to have children in training and recommend this path to fellow trainees. Additional initiatives to normalize and support family planning in medical training for interested trainees are warranted.