Periocular ecchymosis, or periocular bruising, is a common clinical finding. Periocular skin is thin with an extensive vascular network, making this anatomical region prone to bruising. The most common etiology is trauma, but rarely, patients can present with spontaneous periocular ecchymosis (SPE). The pathophysiology of SPE is complex and varied. In this literature review of 121 articles, we assessed the frequency and variety of causation of this infrequent entity. The main finding was that by far the most common diagnosis causing SPE is amyloidosis and neoplasm, most notably neuroblastoma. Amyloidosis accounted for 23% articles (28/121) and neuroblastoma for 17% articles (21/121). Overall, neoplastic processes accounted for 30% of the articles (36/121), raised intracranial pressure and vascular malformations for 19% of the articles (23/121), migraine and atypical headache for 7% of the articles (8/121), while iatrogenic accounted for 5% of the articles (6/121). Through exploration and appreciation of the pathophysiology, we hope to foster a greater understanding in the clinician to establish underlying etiology, from benign to life-threatening, when presented with SPE.