Subdural hematoma (SDH) is a disease commonly seen in both the emergency department and the intensive care unit. Here, we present a case of a woman who developed acute SDH, without any precipitating trauma nor predisposing risk factors. She was managed with hemicraniectomy and SDH evacuation, with subsequent cranioplasty. Routine surveillance imaging found a subsequent, small, and again idiopathic SDH. Comprehensive hematologic workup demonstrated no evidence of coagulopathy. To our knowledge, there are minimal prior case reports published in the literature regarding idiopathic, unprovoked SDH.