AbstractWAIS‐R subtest and composite scale reliabilities, standard errors of measurement, and standard errors of estimate were determined for a sample of psychiatric inpatients (N= 100). For Digit Span and Digit Symbol, test‐ retest stability coefficients were obtained; split‐half reliability coefficients were calculated for all other subtests. With the exception of Object Assembly (rxx=.38), all subtest and composite scale reliability coefficients were large and acceptable. Based on the standard error of measure, the most reliable WAIS‐R subtests were Digit Symbol (.77), Information (1.04), and Picture Completion (1.07). Reliability coefficients for the psychiatric inpatient sample were, in general, comparable to those values reported for the standardization group (Wechsler, 1981). Significant differences were obtained only on the Object Assembly and Vocabulary s