This article considers the remedial and transformative potential of litigation based on legally enforceable socio-economic entitlements, such as the justiciable socio-economic rights contained in the 1996 South African Constitution. It focuses on the interpretation and enforcement of South African prisoners' constitutional rights to dignified conditions of detention (including the provision of adequate medical treatment at state expense) and to consult with medical practitioners of their choice. Although these rights have not yet been the subject of a decision by the South African Constitutional Court, they have been central or incidental to a number of High Court decisions. The article discusses these decisions in an attempt to illustrate, first, that courts are institutionally equipped to effectively vindicate socio-economic rights, secondly, that the enforcement of socio-economic rights may result in tangible and affirmative relief for individual beneficiaries, and thirdly, that victories in socio-economic rights matters may cumulatively have significant transformative potential. The article situates prisoners' rights to medical treatment in the South African social, legal and constitutional contexts, discusses the ambit, scope and remedial potential of the rights, and considers the affirmative and transformative effects of the judgments in which they have been enforced. In particular, the article considers the impact of this distinct body of socio-economic rights jurisprudence on overarching social struggles for improved access to health care services (especially antiretroviral treatment) in South African prisons.