This article describes the findings of an exploratory study which aimed to discover how clinically effective nursing care is fostered among clinical nurse specialists (CNSs) and nurse practitioners (NPs) in an NHS trust in East London. The study was funded by the Central and East London Education Consortium in January 1999. Qualitative approaches included non-participant observation of practice, interviews during observaton and focus group meetings, Findings from the research identify areas that both foster and hinder the ability of the CNSs and NPs to engage in and provide clinically effective nursing care.