There are problems for mental health nurses in using psychiatric diagnoses as outcomes of their nursing assessments and nursing diagnoses present similar issues. However, there is a need in practice to link the assessment to nursing interventions in a meaningful way. This paper proposes that the clinical formulation can be regarded as central to providing this cohesion. The formulation does not merely organize the assessment findings but is also an interpretation or explanation, made in consultation with the client, of what meaning can be attributed to the issues explored in the assessment process. Because this interpretation is dependent on both the client's and the nurse's explanatory frameworks, there are multiple ways of developing the formulation. It is also an evolving and dynamic statement of understanding. A case example is provided in the paper to illustrate how the same case can be interpreted in different ways and the implications this has for the nursing interventions provided.