Static radionuclide images of subacute subdural hematomas demonstrate significant variations in findings over a 3-hr period in the same patient. The lesion can appear, disappear, and reconstitute in an entirely different pattern. This transformation has not appeared in extradural hematomas, and may provide a differential diagnostic sign. In patients with a clinical history or physical findings suspicious for these intracranial hematomas, immediate and sequential delayed static imaging is recommended.