This chapter focuses on subtle neurological signs (SNS) in schizophrenia and illustrates the principles of their assessment and interpretation among persons with neuropsychiatric disorders more generally. Growing appreciation of the role of SNS has led to the development of multiple, structured instruments to assess neurological impairment. These instruments differ markedly in the specific neurological signs assessed and in their psychometric properties. The most commonly employed neurological scales (The Woods Scale, The Heidelberger Scale, The Modified Quantified Neurological Scale, The Cambridge Neurological Inventory, and The Neurological Evaluation Scale (NES)) and their characteristics are described. NES is among the most widely used SNS scales in schizophrenia research. Schizophrenia and other psychoses are characterized by the presence of psychotic symptoms, which are frequently divided into positive symptoms and negative symptoms. Research on neurological signs provides strong evidence supporting the conceptualization of neurological signs as a trait feature of schizophrenia.