The main aims of this action research study were to implement primary nursing in two long-term psychiatric rehabilitation/continuing-care wards and to investigate the effects of the intervention on the quality of nursing care provision. This evaluation took the form of a quasi-expermental time series analysis. A package of measures together with a number of peripheral indicators was used before primary nursing was introduced on each ward and again after primary nursing had become established. The results showed that the implementation of primary nursing led to nurses being more accountable for care, residents who were seen to be more self-sufficient and independent and wards which had an improved enviornment for care and rehabilitation.