To make sense of the complexity of the world so that they can act, individuals and institutions need to develop simplified, self-consistent versions of that world. The process of doing so means that much of what is known about the world needs to be excluded from those versions, and in particular that knowledge which is in tension or outright contradiction with those versions must be expunged. This is ‘uncomfortable knowledge’. The paper describes four implicit strategies which institutions use to keep uncomfortable knowledge at bay: denial, dismissal, diversion and displacement. It concludes by suggesting that ‘clumsy’ arrangements may need to be constructed to ensure that uncomfortable knowledge is not excluded from policy debates, especially when dealing with ‘wicked problems’ where the accepted version excludes knowledge that is crucial for making sense of and addressing the problem.