Aims: As the number of people aged 16-25 referred to mental health services rises, the increasing complexity of their presenting needs is apparent. For those with additional communication and interaction differences, psychological assessment may be especially challenging. They often have long-standing histories of interpersonal challenge, do not find making relationships with others easy and can find conventional information-gathering assessments difficult and at times, even unhelpful. Method/rationale: Educational psychologists (EPs) can make a distinctive contribution in this area because of: (1) their knowledge of adolescent and young adult development; (2) their skills in relational connection in time-limited assessment contexts; and (3) the value they place on person-centred approaches. This paper outlines one approach to psychological assessment that prioritises collaboration with clients aged 16-25 and emphasises understanding the meaning they make of their subjective experience of the world. Findings/implications: The use of projective techniques, where a free-flowing response to a stimulus was used as the basis of a dialogue with the client, is described in the broader context of collaborative assessment. Illustrative case studies that serve as the basis for reflection on experience are explored, with common themes identified. The benefits of the approach, especially in terms of supporting clients and for practitioner learning, are highlighted. Limitations: This approach, whilst facilitated by qualified and trainee EPs, has been developed in a specialist multidisciplinary clinical context. Challenges in using projective techniques as part of collaborative assessments, as well as capacity concerns as regards ongoing training and supervisory requirements, are examined. Conclusions: There are opportunities for the future development of EP practice in this area, as well as promising lines of practice-based research inquiry.