ObjectiveMany young adult female cancer survivors need to use reproductive medicine, surrogacy, or adoption to have a child. This study pilot tested Roadmap to Parenthood, a web‐based, self‐guided decision aid and planning tool for family building after cancer (disease agnostic).MethodsA single‐arm pilot study tested feasibility, acceptability, and obtained effect size estimates of the Roadmap tool. Participants, recruited via hospital‐based and social media strategies, completed a baseline survey (T1), accessed the Roadmap tool (website), then completed surveys at one‐ and 3‐months (T2 and T3, respectively). Feasibility and acceptability were evaluated with rates of eligibility, enrollment, and survey completion, and feedback. Pairwise t‐tests and repeated measures ANOVA evaluated usage effects. Effect size estimates were calculated.ResultsParticipants (N = 98) averaged 31 years old (SD = 5.61); 71% were nulliparous. Enrollment rate was 73%, T1‐T2 completion rate was 80%, and 93% accessed the website. From T1‐T2, participants reported improvements in decisional conflict (p < 0.001; Cohen's d = 0.85), unmet information needs (p < 0.001; Cohen's d = 0.70), self‐efficacy (p = 0.003; Cohen's d = 0.40), and self‐efficacy for managing negative emotions (p = 0.03; Cohen's d = 0.29); effects were sustained at T3. There was no change in reproductive distress (p = 0.22). By T3, 94% reported increased consideration of preparatory actions and 20%–61% completed such actions.ConclusionsThe Roadmap intervention was feasible to conduct, acceptable to users, and led to improvements in key psychosocial outcomes. Future directions will test intervention efficacy in a randomized controlled trial with a larger sample and over a longer period. A web‐based tool may help women make decisions about family building after cancer and prepare for potential challenges.