In this article I consider medieval blood imagery in the paintings, films and journals of Derek Jarman, focusing on works made between 1989-1993. Taking a transhistorical comparative approach, I analyse Jarman's images alongside his medieval sources, primarily Julian of Norwich's Revelations and Gerard of Cremona's translation of Ibn Sīnā's (Avicenna's) al-Qa'n ū n fī al-tibb (Canon of Medicine). In addition, I find my own commonalities between Jarman and the medieval, for example, juxtaposing his Queer series of paintings with MS Egerton 1821. Critics have explored the medieval as a site of historical precedent for the stigmatisation of disease, providing a reservoir of images of leprosy and plague which inform the discourse of AIDS as immoral pollution. However I follow Jarman's lead in seeking new avenues through the medieval in relation to the AIDS crisis. Refusing to accept the discourses which cast his HIV+ blood as the ultimate symbol of pollution and death, Jarman mobilised the aesthetics and imagery of medieval affective devotion as a powerful alternative. Through the deployment of these traditions, HIV+ blood becomes holy blood, the source of salvation, desire, community and healing.