Advocacy is an important tool for translating population health objectives and research findings into policy and practice, as well as for enhancing stakeholder support for programmes and activities with a potential to improve the health of populations. At the inception of modern prisons, health advocacy approaches focused on appealing to humanitarian and religious sentiments of stakeholders to improve the well-being of prisoners. This approach achieved limited results, not least because of persistent apathy of custodial authorities and the public to prisoners’ wellbeing. From the mid twentieth century onwards, a constitutional and human rights approach evolved, with courts becoming actively involved in mandating minimum health standards in prisons. Penal populism eroded public support for a judicial recourse to improving prison health services, and encouraged governments to institute procedural barriers to prisoner-initiated litigation. The author proposes an approach premised on public health principles as an appropriate platform to advocate for improvements in prison health services in this era. Such an advocacy platform combines the altruistic goals of the humanitarian and constitutional rights approaches with an appeal to community's self-interest by alerting the public to the social, financial and health implications inherent in released prisoners suffering from major communicable and chronic diseases re-entering the community.