Arterial injuries of the forearm account for an important fraction of peripheral vascular injuries. Early diagnosis and treatment are important for both function and viability of the extremity. Arterial injuries of the forearm mostly occur as a result of glass or knife cuts and gunshot wounds and the presence of accompanying injuries may facilitate the diagnosis. However, in this case (50-year-old male patient), a piece of nail behaved like a high-energy particle and injured the radial artery without any accompanying lesion. Detection of normal pulses in the radial and ulnar arteries delayed the diagnosis and treatment. This case report aimed to address difficulties in establishing the diagnosis of isolated radial artery injuries.