This chapter analyses shifting dynamics within medical missionary work in Nigeria, from support for British colonialism to humanitarianism. It explores Irish Catholic missionaries as nurses, midwives and physicians from c.1937-1970, to the end of the Nigerian Civil War in 1970. It uses unpublished documents to disentangle, although not disconnect, modern missionary work from colonialism. Using gender as a category of analysis it focuses on women’s work during the Nigerian civil war compared to men’s activities, and how the media focused on one but not the other. By giving voice to the “silenced” in history it argues that there was a significant Nigerian presence in relief work during the war, differing from most research which focuses only on the work of whites. Significantly, in the 1960s and 1970s, Catholic mission hospitals became sites for shifts in the understanding of mission during periods of violence and upheaval. As Catholic women renegotiated their place in an emerging decolonised world, complex relationships developed among Irish sisters, Nigerian nuns, priests, Nigerian chiefs and international peacekeepers. Whereas in the 1930s and 1940s, Catholic sisters saw Africa as a fertile ground for converts, over time the Catholic mission tradition liberalised to promote humanitarianism.