Brain single-photon emission computerized tomography (SPECT), in particular, with perfusion agents or with neuroreceptor imaging radiopharmaceuticals, is rapidly becoming a clinical tool in many neurologic and psychiatric conditions. This imaging modality has been used for diagnosis, prognosis assessment, evaluation of response to therapy, risk stratification, detection of benign vs. malignant viable tissue, and the choice of medical or surgical therapy. We will present our institutional experience in this area, formatting a pictorial review of brain perfusion SPECT on more than 20 types of different neurologic and psychiatric diseases, such as dementia, epilepsy, cerebral palsy, head injury, brain tumor, herpes encephalitis, hypoxic brain damage, vacuities, depression, carbon monoxide (CO) poisoning, and cocaine abuse. This is a demanding procedure as far as the need for trained and experienced physicians and personnel as well as advanced equipment are concerned. However, extraordinary useful clinical information achieved by this technology outweighs the existing challenge. More routine use of this procedure which is unfortunately underutilized in many countries including ours should be encouraged.