The contemporary LGBTQ+ history of Northern Ireland has emerged relatively recently. This article examines two negative models that fed into understandings of male homosexuality between the early 1960s and the end of the 1980s, and some of the discourses that emanated from them. Using contemporary comment, theological and medical writings, and oral history testimonies, this article charts the fortunes of models of ‘sickness’ and ‘sinfulness’. A campaign to secure law reform in the 1970s forced churches to confront the ‘problem’ of homosexuality. I demonstrate the complexity of responses from two major Protestant churches, the tentative emergence of a challenge from radical Christians and how this landscape has been obscured by the notoriety of an infamous fundamentalist campaign. As was the case in England, the notion of homosexuality as a pathology gained traction in Northern Ireland only in the 1950s and 1960s, leading to medical conversion practices, such as aversion therapy, which attempted to ‘cure’ men of same-sex desire. However, discourses conflicted, with regional social conditions resulting in ‘sickness’ co-existing uneasily with ‘sin’. And although it was opposed by a strain of evangelical thought, social conditions fostered by conservative religiosity enabled pathologisation to linger on through the 1980s.