The Kennedy Krieger lead paint study is a landmark case in human experimentation and a classic case in research ethics. In this paper I use the lead paint study to assist in the analysis of the ethics of research on less expensive, less effective interventions. I critically evaluate an argument by Buchanan and Miller who defend both the Kennedy Krieger lead paint study and public health research on less expensive, less effective interventions. I conclude that Buchanan and Miller's argument is flawed but that does not mean that research designed to find less effective interventions cannot be justified in some situations. Based on my analysis, I suggest questions to ask when considering such research and I offer some principles to guide us. In the process, light is shed on the various debates and issues raised by the lead paint study; e.g. standards of care, researchers' responsibilities to research subjects, the distinction between treatment and research and the question of what it is that legitimizes public health research.