ABSTRACT In this paper, I analyse Émilie Du Châtelet’s (1706–49) account of causation which, in turn, is crucial for understanding her philosophical main work, the Institutions de physique (1740/1742). So far, the topic of causation in Du Châtelet’s thought has received but little attention despite its importance. I will show that Du Châtelet’s account of physical causation is that of physical influx much in line with the position taken by some of the most prominent eighteenth-century German metaphysicians at the time of the publication of her Institutions: Martin Knutzen (1713–49), Johann Peter Reusch (1691–1758) and the pre-Critical Immanuel Kant (1724–1804). I will argue that physical influx takes place at the level of simple substances or physical monads, and I will defend my interpretation against the main objection to physical influx: that it conflicts with Leibniz’s non-transfer argument. The ultimate metaphysical details regarding how physical influx has to be understood remain an issue, that of understanding the causality of the cause. This, however, is an issue that other causal theories face, too (in their own way).