Intracranial germinomas may arise in sites besides pineal and suprasellar regions, which we call intracranial ectopic germinomas (IEGs). In this article we evaluated the rationality of radiotherapy in IEGs when histopathological evidence could not be obtained. Criteria for initiating experimental radiotherapy in patients with clinically presumed IEGs was established according to the reports published in this field and the experience gained from our five histopathologically verified IEG patients. When patients suspected to have IEGs met the criteria, radiotherapy following standard protocol was performed. Strict criteria was also employed to evaluate the effectiveness of radiotherapy after completion of initial experimental dose of radiation and to determine whether total dose of radiation should be delivered. Seven patients clinically suspected to have IEGs met the criteria for radiotherapy. Radiotherapy was evaluated as effective in six patients immediately after completion of initial experimental dose of radiation and the remaining dose was delivered. However, effectiveness of initial experimental radiotherapy was not testified until 2 months later in the other one patient. Total dose of radiation was completed and satisfactory results achieved in all seven patients. In conclusion, the histopathological verification is not mandatory for radiotherapy in patients with IEGs when histopathological evidence can not be obtained. Strict criteria should be followed to enroll patients to undergo experimental radiotherapy.