Starting from the works by Aselli on the milky veins and Harvey on the motion of the heart and the circulation of the blood, the practice of vivisection witnessed a resurgence in the early modern period. I discuss some of the most notable cases in the century spanning from Aselli’s work to the investigations of fluid pressure in plants and animals by Stephen Hales. Key figures in my study include Johannes Walaeus, Jean Pecquet, Marcello Malpighi, Reinier de Graaf, Richard Lower, (...) Anton Nuck, and Anton de Heide. Although vivisection dates from antiquity, early modern experimenters expanded the range of practices and epistemic motivations associated with it, displaying considerable technical skills and methodological awareness about the problems associated with the animals being alive and the issue of generalizing results to humans. Many practitioners expressed great discomfort at the suffering of the animals; however, many remained convinced that their investigations were not only indispensable from an epistemic standpoint but also had potential medical applications. Early modern vivisection experiments were both extensive and sophisticated and cannot be ignored in the literature of early modern experimentation or of experimentation on living organisms across time. (shrink)