Drawing on the work of Sianne Ngai in Ugly Feelings (2005), in this essay we focus on two examples from early fifteenth-century medieval literature that represent medieval books as ‘ugly’ either because they arouse negative feelings of aversion or disgust or because they are considered in some way aesthetically lacking or inadequate. Christine de Pizan’s Livre de la cité des dames and Margery Kempe’s Book of Margery Kempe present women’s involvement with troubling or difficult books. The ‘ugly book feelings’ which both narrators encounter challenge not only their authority as writers, but their very sense of self. Such feelings, however, are transitory when placed in narrative context: in the two examples we discuss, a single material text serves as the catalyst for a moment of emotional transformation which may be spiritual and/or intellectual. Attending to literary representations of ugly book feelings, we argue, complements existing scholarship on late medieval women’s relationship to material textual culture by placing such feelings at the centre of a broad emotional spectrum.