Mental fictionalism is the view that, even if mental states do not exist, it is useful to talk as if they do. Mental states are useful fictions. Recent philosophy of mind has seen a growing interest in mental fictionalism. To date, much of the discussion has concerned the general features of the approach. In this paper, I develop a specific form of mental fictionalism by drawing on Kendall Walton’s work on make-believe. According to the approach I propose, talk of mental states is a useful pretence for describing people and their behaviour. I try to clarify and motivate this approach by comparing it to well-known alternatives, including behaviourism, instrumentalism and eliminativism. I also consider some of the challenges that it faces.