This article presents a theoretical critique of the employment provisions of the Disability Discrimination Act (DDA) (1995), focusing on the definition of disability. It argues that the underpinning medical assumption of the statutory definition of disability is detrimental to the achievement of disability equality in the workplace and is problematic for practitioners and Employment Tribunals. In particular there are four areas of significant confusion arising from the need for medical evidence, the lack of congruence between managerial and legal definitions, the focus on the negative aspects of disability and the fact that disability is often hidden. By exploring these four themes and drawing on comparisons with the other equality laws, the article concludes that the definition of disability contained in the DDA (1995) contradicts many of the principles of the liberal equality framework that underpins it. Finally the article considers the public policy implications and suggests a new statutory approach.