OBJECTIVE Juvenile nasopharyngeal angiofibroma (JNA) is a rare, benign tumor of the nasopharynx, exclusively affecting males in their teens and twenties. Historically, it has been thought that JNAs primarily receive their blood supply from the ipsilateral external carotid system. We demonstrate in our case series and literature review that bilateral vascular supply in these tumors is, in fact, very common. METHODS Case series and literature review. METHODS We present four consecutive cases of JNA in a three-year period from a major tertiary care center. A literature review on the topic of vascular supply in JNA was performed. RESULTS The first patient's preoperative angiogram demonstrated only right-sided blood supply. However, significant bleeding was encountered, and an intraoperative angiogram showed significant new vascularization from the left ascending pharyngeal artery (APA), which was embolized. The surgery was completed successfully without further significant hemorrhage after converting to an open approach. Preoperative angiograms from the next three patients demonstrated bilateral vascular supply. Embolization and endoscopic resection was successful in these cases. Review of the literature demonstrates that bilateral vascular supply is not commonly documented; however, it may be more frequent than previously thought. Other series demonstrate bilateral vascularity from 0% to 100%. Combining patients from nine studies, including our own, we found that 57 of 157 (36%) patients had tumors with bilateral vascular supply. CONCLUSIONS Bilateral vascular supply may be an underappreciated factor in JNA, and thorough radiographic investigation via angiography of bilateral carotid systems should be routinely done preoperatively.