Adrenal metastasis from colorectal cancer occurs in the presence of multiple synchronous metastases at other sites. We report a case of heterochronous solitary adrenal metastasis from rectal cancer. A 55-year-old man underwent anterior resection with D3 lymph node dissection for rectal cancer. The pathological stage of the tumor was III b, and adjuvant chemotherapy with mFOLFOX6 was administered for 6 months. Eighteen months after surgery, abdominal computed tomography(CT) revealed right solitary adrenal metastasis. His tumor marker levels were considerably elevated; therefore, he received preoperative chemotherapy with FOLFIRI plus bevacizumab(BV). After preoperative chemotherapy, his tumor marker levels decreased, and CT and FDG-PET/CT did not uncover any other metastatic lesions. The patient was diagnosed with solitary adrenal metastasis, and right adrenalectomy was performed. Histological examination confirmed the tumor to be adrenal metastasis from rectal cancer, and the histopathological Grade was 2. The patient received adjuvant chemotherapy with mFOLFOX6, and he is alive 7 months after adrenalectomy without evidence of recurrence. Adrenalectomy is recommended for solitary adrenal metastasis from colorectal cancer. Additionally, adrenalectomy after preoperative chemotherapy is an effective strategy for patients with solitary adrenal metastasis and high tumor marker levels.