This paper considers the potential for the Mental Capacity Act (MCA) of England and Wales to incentivise the exclusion of people with dementia from research. The MCA is intended to standardise and safeguard the inclusion of people with cognitive impairments in research. This entails various procedural requirements, which in pressurised research contexts can lead researchers to exclude people with dementia as a means of simplifying bureaucratic constraints. I consider the risks of an ‘unethical ethics’, wherein procedural ethics indirectly causes the exclusion of people with dementia from research, undermining historic successes toward increased inclusivity. I suggest several solutions, including enhanced sensitivity to impairments and shifting the burden of proof from justifying inclusion to justifying exclusion. The paper responds to the ‘ethics creep’ tradition in procedural ethics, and critical appraisals of capacity legislation in dementia research. This approach recognises that institutional research ethics is itself a major ethical concern and can unwittingly beget unethical practices. Dementia researchers must be alert to such unethical ethics.