This study aimed to explore the thoughts and experiences of young men with cancer regarding the risk of infertility and the oncofertility counseling they received at diagnosis and during their cancer trajectory.This qualitative study was conducted from October 2023 to February 2024 at the Copenhagen University Hospital-Rigshospitalet. Inclusion criteria were male adolescents and young adults with cancer aged 15-29 years. We conducted fourteen individual, semi-structured, qualitative interviews with male adolescents and young adults with either leukemia, lymphoma, or testicular cancer. Data were analyzed using thematic analysis.Three themes were identified: (1) Young men with cancer have existential thoughts about future children; (2) young men call for information and communication about the risk of reduced fertility chances after cancer; (3) young men experience challenges related to cryopreservation of semen.Young men desire children after cancer and fertility preservation offers reassurance. Psychological and physical fertility issues often impact body image and masculinity during cancer. Oncofertility counseling is limited, usually brief at diagnosis; however, discussions on treatment-related fertility challenges remain sparse during follow-up. Young men often experience stress related to fertility preservation at diagnosis, which they feel is not recognized by healthcare professionals. This underscores the need for better oncofertility education for healthcare professionals and closer collaboration between oncologists, hematologists, and fertility specialists.