PurposeThe purpose of the study is to evaluate the feasibility of a self-help web-based intervention to alleviate sexual problems and fertility distress in adolescents and young adults with cancer.MethodsTwenty-three persons with cancer (19 women and 4 men, age 18–43, 1–5 years post-diagnosis of lymphoma, breast, gynecologic, central nervous system, or testicular cancer) were recruited to test a 2-month web-based program targeting sexual problems or fertility distress. The programs were organized in modules with educational and behavior change content, including texts, illustrations, exercises, and video vignettes. The program also included a discussion forum and an “ask the expert” forum. In addition, the sexuality program offered two telephone consultations. Feasibility (regarding demand, acceptability, preliminary efficacy, and functionality) was evaluated with the website system data, telephone interviews, continuous online evaluations, and study-specific measures.ResultsFifteen participants completed four modules or more. Most of the program features were used and well accepted by these “committed users.” The web-based format enabled flexible use by participants with diverse needs. Preliminary efficacy was indicated by self-reported increased knowledge and skill in handling sexual problems and fertility distress. The website was easy to use and functioned well technically.ConclusionsThe present study indicated that this web-based intervention was feasible for adolescents and young adults with cancer. The effectiveness of the intervention in decreasing sexual problems and fertility distress will be tested in a population-based randomized controlled trial for adolescents and young adults with cancer.Trial registration: ISRCTN36621459.