Two boys aged 8 and 12 years presented with intracranial germinoma manifesting as cerebral hemispheric atrophy, hemiparesis, and decline in academic performance. First magnetic resonance (MR) imaging showed no enhanced lesions, but follow-up MR imaging obtained 12 or 23 months after the first visit showed new mass lesions in the temporal lobe or pituitary gland. Biopsy of these lesions resulted in a histological diagnosis of germinoma. Chemoradiation therapy produced complete remission but both patients continued to manifest mild hemiparesis and impaired cognitive function. Review of 18 previous and our 2 patients presenting with hemispheric atrophy revealed strong male predominance (18:2), mean age of 12.8 ± 5.2 (standard deviation) years, hemiparesis in all patients, and cognitive decline in 9 patients. Initial MR imaging detected mass lesions in only 9 patients, but follow-up MR imaging performed 10-38 months later detected new mass lesions in 5 patients. Radiation with/without chemotherapy provided good tumor control in all patients, but none of the 9 patients with cognitive dysfunction recovered their intellectual ability. We recommend early diagnosis based on biopsy of the atrophic site and timely treatment to improve the quality of life in these patients.