Aim: This study examined the psychosocial impact of experiences of care at the end-of-treatment for Adolescents and Young Adults (AYAs) with cancer. Methods: A cross-sectional survey was conducted with 209 AYAs, aged 15-24 years at diagnosis, of which 162 (77.5%) had finished cancer treatment. The survey response rate was 29%. Patients were recruited through population-based cancer registries in Victoria and New South Wales, Australia. Questions assessed experiences (including the provision of information and support) at treatment end and AYA’s quality of life. Results: Participants were on average 9 months post-diagnosis (range 3-24 months) and had received surgery (76.5%), chemotherapy (56.2%) and/or radiotherapy (30.2%). At treatment end, a minority reported definitely being given a follow-up care plan (27%), a summary of their care (22%), information on how to manage ongoing side-effects (24%) or new symptoms to look for (32%). Only 21% reported being offered help returning to daily life and 19% reported being told about the emotions young people might face after finishing treatment. A scale constructed from these items indicated that more supportive end-of-treatment experiences were linked with better functional (B[95%CI]=5.45[2.37-8.52], p=.001), emotional (B[95%CI]=2.40[.24-4.56], p=.030) and social well-being (B[95%CI]=5.46[2.79-8.13], p<.001). The 39% of AYAs referred to emotional support services displayed better emotional (B[95%CI]=2.52[.46-4.58], p=.017) and social well-being (B[95%CI]=2.41 [.01-4.81], p=.049) than those not referred. Having follow-up tests and appointments coordinated by the health service to reduce hospital visits definitely occurred for 45% of patients and was associated with higher functional (B[95%CI]=2.10[.05-4.14], p=.044) and social (B[95%CI]=1.91[.11-3.71], p=.038) well-being. Conclusions: Results demonstrate the need for end-of-treatment support and information provision to be more routinely provided to AYAs with cancer. Supportive experiences at the end of treatment were positively associated with the psychosocial well-being of AYAs as they enter the survivorship phase.