In this review, the authors describe the Transcranial Doppler sonography technique (TCD). They also make an analysis of the up-to-date publications on the use of TCD in the studies on schizophrenia. The current studies show a promising potential of TCD. Its benefits are connected with high time-output, low-cost and only slightly invasive character. The difficulty of using TCD lies in the experience of the technician and the quality of the equipment. What should be kept in mind, is the fact that the data received in the TCD study is only an indirect indication of CNS activity. The research described here shows two potential directions of applying TCD to schizophrenia studies. One of them concerns the intensity of psychotic symptoms as well as the medications given on the changes in transcranial blood-flow. The second connects the search for cognitive function disorders and the activity of certain brain regions with the transcranial blood-flow changes resulting from them. In such a protocol of research, where TCD technique is simultaneously applied along with an evaluation through neuropsychological tests, one could speak of a functional transcranial study--fTCD. The studies mentioned here, have only a pilot character owing to a low number of subjects studied. However, a picture of subtle differences in cerebral blood flow of schizophrenic patients does appear. The use of TCD requires further, deeper studies with the participation of a larger group of patients, along with a neuropsychological tool application.