Subdural hematoma in infants can be caused by abuse, and is thought to be more likely if subdural hematoma is associated with retinal hemorrhage and cerebral edema. In Japan, few doctors disagree that cases of subdural hematoma with retinal hemorrhage and cerebral edema with multiple findings on the body are more likely to have been caused by abuse rather than by household accident. On the other hand, in cases where there are no other significant physical findings, only subdural hematoma and retinal hemorrhage, there is a difference of opinion as to whether the injury was caused by an accident or abuse. The reason for this is that neurosurgeons in Japan promoted the concept that infants can develop subdural hematomas and retinal hemorrages due to minor trauma at home before the concept of abusive head trauma became known. In addition, the age distribution of subdural hematomas in Japan differs from that in other countries, with peaks at around 8 months, and the reason for this remains unclear. Therefore, the etiology of infant subdural hematoma in Japan needs to be investigated in greater detail.