Title. Benchmarks for effective primary care-based nursing services for adults with depression: a Delphi study. Aim. This paper is a report of a study conducted to identify and gain consensus on appropriate benchmarks for effective primary care-based nursing services for adults with depression. Background. Worldwide evidence suggests that between 5% and 16% of the population have a diagnosis of depression. Most of their care and treatment takes place in primary care. In recent years, primary care nurses, including community mental health nurses, have become more involved in the identification and management of patients with depression; however, there are no appropriate benchmarks to guide, develop and support their practice. Method. In 2006, a three-round electronic Delphi survey was completed by a United Kingdom multi-professional expert panel (n = 67). Findings. Round 1 generated 1216 statements relating to structures (such as training and protocols), processes (such as access and screening) and outcomes (such as patient satisfaction and treatments). Content analysis was used to collapse statements into 140 benchmarks. Seventy-three benchmarks achieved consensus during subsequent rounds. Of these, 45 (61%) were related to structures, 18 (25%) to processes and 10 (14%) to outcomes. Conclusion. Multi-professional primary care staff have similar views about the appropriate benchmarks for care of adults with depression. These benchmarks could serve as a foundation for depression improvement initiatives in primary care and ongoing research into depression management by nurses.