The purpose of this review is to explore the literature on the experience of adolescents and young adults (AYAs) having cancer treatment in an adult setting, rather than on a specialist adolescent cancer unit. The integrative review method was used to explore the current literature. Primary research on the topic was located systematically and then synthesized into a thematic narrative. The experience of AYAs undergoing treatment in an adult setting was generally negative. This can be attributed to three themes: feeling isolated in the adult setting; the lack of empathy from staff working in the adult setting; and the inappropriateness of the adult environment for this age group. As many AYAs with cancer will continue to have treatment in adult settings, staff working in this environment should be aware of the negative experience of this cohort and the impact this can have on a vulnerable group of patients. Staff could consider simple ways of improving the AYA experience, such as connecting AYA patients with their peers to reduce isolation; adapting their approach to take account of the unique emotional needs of this age group; and considering ways of making the environment more welcoming and age-appropriate.