Aim: The provision and implementation of early intervention for psychosis services (early intervention services [EIS]) has received increasing attention over recent years. Maximizing engagement with EIS is of clinical and economic importance, and exploring the experiences of those who access EIS is vital. Although research has been conducted exploring the experiences of engaging with EIS from both a service user and carer/family member point of view, these data have not been systematically collated to generate new understanding. The primary aim of this study is to review, critically appraise and synthesize qualitative findings relating to the experiences of service users and/or carers and family members engaging with EIS.; Methods: Four databases were systematically searched. Studies were analysed using an inductive thematic analysis approach, within a critical realist epistemological framework. Studies were critically appraised using the critical appraisal skills programme tool.; Results: Fourteen papers were identified for inclusion. Three main themes were identified: the importance of a personal relationship with an EIS staff member, the impact of this relationship and consideration of life after EIS. The importance of a strong relationship with EIS staff was the most prominent theme throughout the papers reviewed.; Conclusions: The quality of the therapeutic relationship with at least one EIS staff member was the single most important factor in determining whether the experience of accessing EIS was a positive or negative one. The majority of the studies reviewed were conducted in the United Kingdom or Australia. Therefore, more research across countries is needed to understand transferability of findings.