This report describes the case of a gentleman aged 59 years presenting with low-back pain, who had underwent radical prostatectomy for prostate cancer 8 years ago. On evaluation, a slightly elevated serum alkaline-phosphatase level prompted a search for bone metastases. Although x-ray radiography and a bone scan were apparently normal, an MRI scan revealed the presence of metastatic marrow infiltration in the lumbar vertebrae. The patient subsequently was initiated on therapy with androgen-deprivation therapy and bisphosphonates, and currently enjoys symptom-free and progression-free survival. The images in this paper intend to impress upon the limitations of bone scan and x-ray radiography with regard to the detection of vertebral marrow infiltration in the absence of cortical bone invasion. In addition, a brief review of the pathophysiology of vertebral metastases arising from prostate cancer is included.