A deficit in cognitive suppression is a trait of patients with schizophrenia. Cognitive suppression is the ability to control or suppress irrelevant information and to adopt relevant responses instead. This ability is a basic skill which is essential to maintain a normal well-adjusted life. We need to suppress distracting information in order to focus attention, to suppress irrelevant cues in order to retrieve particular memories, and to suppress habitual responses in order to make adaptive choices (Dillon & Pizzagalli, 2007). The purpose of this study is to investigate the effects of transcranial direct current stimulation (tDCS) on information suppression in schizophrenic patients. This is a noninvasive technique of brain stimulation that induces prolonged functional changes in the cerebral cortex through the application of a weak direct current to the scalp (Nitsche & Paulus, 2001; Nitsche et al., 2003, 2004; Antal et al., 2004). The aim of this study is to test whether anodal and cathodal tDCS differentially modify performance on several cognitive tasks when applied to the left/right dorsolateral prefrontal cortex (DLPFC).