Diachronically, Mesopotamian data pertaining to the religious spheres point to a transversal notion that deities were considered responsible for every cause–effect event observed/experienced by humans in their natural/cosmic surroundings. Such notion is especially visible on texts pertaining to the restoration of human health, where such an aspect was ultimately considered as a divine prerogative. Yet, these textual data also show how natural elements were basilar to the success of healing practices when thoroughly manipulated by specialists. Their examination through a perspective that intertwines the apparatus of History of Religions and Environmental History thus reveals great potential for contributing to the topic of human/nonhuman entanglements in the longue durée. With this paper, we propose to revisit the uses of aquatic fauna as displayed in Babylonian and Assyrian healing texts dated to the second half of the 2nd millennium and the first half of the 1st millennium BC. Although at a preliminary stage, our research has been guided by the combined theoretical-methodological perspective above-mentioned, aiming at highlighting the great importance conferred to these animals. Ultimately, we aim at stressing the importance of addressing the dependence of Mesopotamian specialists and patients on such elements of Nature to better understand this ancient context.