Brazil imported more enslaved Africans than any other slave-owning society in the Americas, and it was the last country in the western hemisphere to abolish the institution. Whereas many enslaved persons toiled on plantations and in mines, urban slavery was also prominent, with enslaved men carrying coffee through the streets and enslaved women washing clothes. One gendered aspect of urban slavery in 19th-century Brazil included slave owners renting out enslaved women as wet nurses to breastfeed the children of elite families. This article reviews medical dissertations, debates, and journal articles, as well as advertisements for wet nurses, showing that physicians believed that enslaved women’s milk was both nutritionally and morally inferior to white women’s milk. In the latter half of the 19th century, physicians viewed abolition as the only answer to what they deemed the increasingly “dangerous” practice of enslaved wet nursing, which they believed was the root cause of high infant mortality rates across races and classes. Readers should consider the ethical dilemmas of the practice of enslaved wet nursing, which often resulted in the violent separation of mother and child.