Investigated the Weigl's diagnostic significance by correlating it with several psychometric and personal variables, including degree of brain dysfunction. Forty‐three male, veteran, psychiatric patients were administered the complete WAIS, Hooper, Benton, and Weigl, and their ward psychiatrist estimated presence and degree of brain dysfunction. Although uncorrelated with brain dysfunction, the Weigl did correlate significantly with 13 of the 19 study variables involved in assessment of brain function. Factor‐analytic studies showed that the Weigl loaded significantly on the factor associated with neurological function. It was discovered that when a patient who is being screened can perform the conceptual requirements of the Weigl, then additional conceptual‐verbal tests (e. g., Similarities) are less useful in discriminating organicity than perceptual tests (e. g., Object Assembly). When a patient cannot shift on the Weigl, then further conceptual tests will be useful.