This is the case of a 67-year-old woman with a sudden on-set of lower abdominal pain and pre-shock. A physical examination showed signs of pan-peritonitis. Emergency was operation performed 5 hours after the onset. She had undergone Hartmann's operation for rectal cancer. Six month after the operation, abdominal CT scan revealed the mass of puriform acites, about 20 mm in diameter, in the right suprarenal region. Right adrenalectomy was performed with a diagnosis of solitary adrenal metastasis from rectal cancer. Histologically, the metastatic adenocarcinoma was moderately differentiated to the adrenal medulla. The capsule was kept intact, and no swelled lymph nodes were found around the adrenal gland. There have been no signs of recurrence for 4 years after the operation.