In this article we argue that the concept of need is as vital for moral theory as it is for moral life. In II we analyse need and its normativity in public and private moral practice. In III we describe simple cases which exemplify the moral demandingness of needs, and argue that the significance of simple cases for moral theory is obscured by the emphasis in moral philosophy on unusual cases. In IV we argue that moral theories are inadequate if they cannot describe simple needs-meeting cases. We argue that the elimination or reduction of need to other concepts such as value, duty, virtue or care is unsatisfactory, in which case moral theories that make those concepts fundamental will have to be revised. In conclusion, we suggest that if moral theories cannot be revised to accommodate needs, they may have to be replaced with a fully needs-based theory.