Objective: To investigate the role of magnetic resonance imaging (MRI) of bone metastases in nonseminomatous germ cell tumors. Methods and Materials: There were 5 consecutive patients with bone metastases from nonseminomatous germ cell tumors treated between 2003 and 2006 who underwent imaging studies, including MRI. The characteristic imaging findings are discussed in the light of the clinical course. Results: Of the 5 patients, 3 had symptoms related to bone involvement at diagnosis. All patients received conventional x-ray of their bony lesions, but only 1 of them was considered abnormal. Skeletal MRI was obtained in all patients. A bone scan was available in 3 cases with spinal involvement. It was normal in 1 case and detected only a minority of the lesions visible on MRI in the other 2 cases. Follow-up MRIs were available in all patients. A partial resolution of bone involvement during chemotherapy was observed in only 1 of them. In 2 cases, there was a slight progression of a diffuse alteration of the bone marrow during treatment. In 1 patient, severe spinal bone marrow changes were visible on MRI 2 years after cessation of treatment without evidence of disease recurrence. Conclusions: MRI may disclose bone metastases in nonseminomatous germ cell tumors, which otherwise may be missed. MRI findings of bone lesions during treatment do not directly reflect the course of the disease and have to be interpreted with caution using clinical information.