This article offers vascularity as a multi‐dimensional imaginary for the interspecies entanglements constituting Ayurvedic leech therapy. Whether, when, where, and how a leech decides to bite, suck, and release comprise pivotal junctures in leech therapy as practiced in southern Kerala, India. In the course of leech–human intra‐actions, leeches translate matter, providing sensory mediation, relief, and amusement. Enmeshed in social and ecological relations inflected by gender, religion, class, and caste, this analysis of Ayurvedic leech therapy reframes questions of agencies starting with and from the viewpoint of the vascular capacities of leeches in their interactions with humans. This image of vascularity provides an analytic for the emergent agencies of humans and leeches constituted by sensory intra‐actions at branching points in this multispecies clinical practice.