Values Based practice is a new skills-based approach to balanced clinical decision making where complex and conflicting values are in play. In medicine, complex and conflicting values have traditionally been associated in particular with ethical issues of the kind raised by treatment. This paper will use a clinical case history to show that complex and conflicting values are no less important in diagnostic assessment than in treatment. Various interpretations of the importance of values in diagnosis in psychiatry will be outlined. In the final part of the presentation I will outline some of the practical applications of a values-based approach in supporting policy and service developments that are both evidence based and person centred.