The development of integrated care through the promotion of 'partnership working' is a key policy objective of the Scottish Executive, the administration responsible for health services in Scotland. This paper considers the extent to which this goal is being achieved in mental health services, particularly those for people with severe and enduring mental illness. Distinguishing between the horizontal and vertical integration of services, exploratory research was conducted to assess progress towards this objective by examining how far a range of functional activities in Primary Care Trusts (PCTs) and their constituent Local Health Care Co-operatives (LHCCs) were themselves becoming increasingly integrated. All PCTs in Scotland were surveyed by postal questionnaire, and followed up by detailed telephone interviews. Six LHCC areas were selected for detailed case study analysis. A Reference Group was used to discuss and review emerging themes from the fieldwork. The report suggests that faster progress is being made in the horizontal integration of services between health and social care organisations than is the case for vertical integration between primary health care and specialist mental health care services; and that there are significant gaps in the extent to which functional activities within Trusts are changing to support the development of integrated care. A number of models are briefly considered, including the idea of 'intermediate care' that might speed the process of integration.