Since its enactment in 1999–2000, the 50% capital gains tax (CGT) discount has become an entrenched feature of the Australian tax system. The CGT discount is effectively a tax rate preference that, we argue, remains in place despite its tax policy shortcomings. These include that the CGT discount is inequitable from the perspective of horizontal and vertical equity, and it is inefficient in that it may encourage an overinvestment in assets that produce most of their return in the form of capital gains. This article is a critique of the CGT discount which draws on a chronologically organised analysis of the views and commentary on the CGT discount from individuals and organisations outside of government. Views and commentary on the CGT discount are sourced from the news media, submissions to government discussion papers, and other publicly available information. This article critically evaluates the policy basis and evidence for the 50% CGT discount and is, in part, concerned with whether there is an overall justification for the preference. It is argued that the justifications made by policymakers in favour of the CGT discount, at the time of its enactment, lacked sound tax policy foundations. It follows that the case for the CGT discount continuing in its current form is diminished.