This article considers the interpretive significance of legislative inaction. Section I considers the nature of arguments based on legislative inaction. Section II explores the practical, conceptual and constitutional problems with trying to rely on legislative inaction as an interpretive aid. Section III concludes that attempts to draw inferences from legislative inaction alone are deeply flawed, but that inferences might legitimately be drawn from inaction if it forms part of the context against which the legislation is enacted. Even then, however, there are practical difficulties in determining what inferences to draw.