ObjectiveThe research project addressed the need to support young adults with issues relating to sexuality and relationships though the development of guidance and standards for practice.MethodsAn action research project underpinned by an interpretivist qualitative framework. Participants were recruited to the project via three hospices in the UK. Data from four focus groups were analysed thematically using a process of constant comparison.ResultsSixteen young adults with life-limiting or life-threatening conditions aged 21–33 years participated in the study. Three significant themes were identified: sexuality and the transition to adulthood, recognising the significance of sex and relationships, and realising sexual rights.ConclusionSexuality and relationships play an important role in the transition to adulthood for people with life-limiting or life-threatening conditions living in the UK. While young adults with these conditions may have considerable support needs, it is important to balance this with the freedom to exercise choice and to make independent decisions. Sex negativity can have an adverse impact on the experiences of young adults and creates barriers. Improved ongoing access to sex education and the provision of enabling environments that afford privacy and safety are important to support young adults with sexuality and relationships.