African marketplaces have long been understood as ambivalent spaces; as sites of compliance and transgression, domination and resistance. This ambivalence comes into sharp focus in the urban marketplaces that have absorbed a large proportion of the African workforce over the past four decades. One the one hand, urban markets offer opportunities for the forging of new relationships, or ‘fictive kin’, beyond the confines of consanguinity and affinity. However, on the other hand, they are fiercely competitive places in which strangers skilfully intrude into one's life. Succeeding in the market therefore requires the striking of a skilful balance between accumulation and redistribution, disclosure and concealment. This article presents an analysis of the everyday interactions and exchanges facilitated by the movements of a waste picker in Nakasero market, the oldest marketplace in Kampala, Uganda. Amid the current emphasis on improvization and provisionality as key features of urban African life, it demonstrates the importance of long-standing cultural idioms, such as omutima (‘heart’), in providing structure and meaning to the interactions of urban African inhabitants.