Spinal subarachnoid hemorrhage (SAH) due to solitary spinal aneurysm is extremely rare. A 45-year-old female patient visited the emergency department with severe headache and back pain. Imaging studies showed cerebral SAH in parietal lobe and spinal SAH in thoracolumbar level. Spinal angiography revealed a small pearl and string-like aneurysm of the Adamkiewicz artery at the T12 level. One month after onset, her back pain aggravated, and follow-up imaging study showed arachnoiditis. Two months after onset, her symptoms improved, and follow-up imaging study showed resolution of SAH. The present case of spinal SAH due to rupture of dissecting aneurysm of the Adamkiewicz artery underwent subsequent spontaneous resolution, indicating that the wait-and-see strategy may provide adequate treatment option.