Purpose: Haemangiomas and vascular malformations are not easy to differentiate clinically. We describe a patient who was initially thought to have a scrotal venous malformation (VM) but after pathological examination was diagnosed to be afflicted with an arteriovenous malformation (AVM) with a micro-fistula in pathorogical photo. We think that even if there are suspicions of VM before the operation, the importance of resection with an ample margin of safety is indicated. Material and Method: A 38-year-old man who noticed a mass in his scrotum. The patient was seen at our hospital in May 2009 with concern for progression of the scrotal mass. That mass appeared to indicate a simple case of VM of the scrotum. Result and Conclusion: A biopsy of the mass was performed and was diagnosed to be a micro-fistula AVM, with no tumour growth in the vascular endothelial cells. Resection was performed in September 2009. And there is no recurrence. Even if there are suspicions of VM before the operation, the importance of resection with an ample margin of safety is indicated.