A 29-year-old female presented with pain and a palpable mass in the left wrist. Imaging demonstrated a multiloculated cystic mass adjacent to the radial aspect of the scaphoid, which was intimately associated with and appeared to arise from the wall of the radial artery and its dorsal branch. The mass was surgically resected. The histological analysis confirmed the presence of adventitial cystic disease (ACD) of the radial artery. In addition, within a year time span, a second 34-year-old male patient presented with a palpable mass in the right hand. Imaging demonstrated a cystic mass encasing the dorsal carpal branch of the radial artery and its terminal vessels to the thumb and index finger. The diagnosis of ACD was raised based on MR imaging. Histological analysis confirmed the presence of an adventitial cyst. ACD of the arteries is a rare disorder of unknown etiology, which usually involves the popliteal artery. Less common sites of involvement include the external iliac, common femoral, radial, and ulnar arteries. To our knowledge, there have only been six previous case reports of adventitial cystic disease involving the radial artery. The imaging features, histology, differential diagnosis, pathogenesis, and treatment are discussed.