Successive legislation has underscored the importance of assessments that are sensitive to the needs of carers and take into account their ability and willingness to continue caring. This paper synthesizes qualitative and quantitative findings from a continuing programme of carer-related research that began in 1993 and has continued in parallel with legislative changes. It considers the process and characteristics of carer assessment from the perspectives of carers for individuals with a range of health and social care needs, and practitioners. This paper explores the assessment of carer need over time and highlights the considerable and enduring gap between policy and practice. It considers practitioners' reluctance to offer separate carer assessments, identifies confusion relating to the interpretation of eligibility criteria and documents the limited contribution of health service staff. The need for an evidence-based framework for good practice, that distinguishes between carer needs, service provision and carer outcomes, is highlighted. The paper concludes by identifying key changes that are necessary to promote future good practice, such as staff training and information strategies and the need for practitioners to engage with carers as partners in the care process.