A substantial body of evidence supports the value of exercise inthe treatment of people with depression. The guidelines for exerciseprescription, however, are limited, and based on those developed forhealthy populations. This article explores the evidence for exercisein the treatment of depression and the role mental health nursesmay play in the delivery of this information. A model of exerciseprescription is put forward based on the available evidence andtaking into account the challenges faced by mental health nursesand people with depression.