Background-Insight in schizophrenia is defined as awareness into illness, symptoms, and need for treatment and has long been associated with cognition, other psychopathological symptoms, and several adverse clinical and functional outcomes. However, the biological basis of insight is not clearly understood. Objective-The aim of this systematic review was to critically evaluate and summarize advances in the study of the biological basis of insight in schizophrenia and to identify gaps in this knowledge. Methods-A literature search of PubMed, CINAHL, PsycINFO, and EMBASE databases was conducted using search terms to identify articles relevant to the biology of insight in schizophrenia published in the last 6 years. Articles that focused on etiology of insight in schizophrenia and those that examined the neurobiology of insight in schizophrenia or psychoses were chosen for analysis. Articles on insight in conditions other than schizophrenia or psychoses and which did not investigate the neurobiological underpinnings of insight were excluded from the review. Results-Twenty-six articles met the inclusion criteria for this review. Of the 26 articles, 3 focused on cellular abnormalities and 23 were neuroimaging studies. Preliminary data identify the prefrontal cortex, cingulate cortex, and regions of the temporal and parietal lobe (precuneus, inferior parietal lobule) and hippocampus as the neural correlates of insight. Discussion- A growing body of literature attests to the neurobiological basis of insight in schizophrenia. Current evidence supports the neurobiological basis of insight in schizophrenia and identifies specific neural correlates for insight types and its dimensions. Further studies that examine the precise biological mechanisms of insight are needed to apply this knowledge to effective clinical intervention development.