The growth of “atypical” forms of work has been one of the defining features of the UK labour market over recent decades, and regulating these evolving working arrangements represents an important challenge for labour law. This article focuses on the treatment of one longstanding form of atypical working arrangement, namely casual or intermittent work in British labour law. It argues that the treatment of individuals working on a casual basis represents an ongoing and unresolved problem, and that the failure to adequately protect casual workers is a serious lacuna that has not been addressed by recent developments in common law or statute and requires the attention of the legislature. In addition, we argue that in addressing the issue of casual work the focus needs to move beyond the issue of employment status and entitlement to existing rights. While undoubtedly important, it is also crucial to answer the question of what additional substantive rights are required to address the specific vulnerabilities and harms faced by casual workers.