Development of the Everyday Indicators of Impaired Cognition (EIIC) Scale to assess nursing home residents for performance errors in four domains of cognitive functioning is reported. The EIIC had strong content validity, with indices ranging from 0.7 to 1.0. Factor analyses of data from two independent samples (N = 198, N = 107) confirmed four factors: abstract thinking, judgment, language, and spatial skills. Cronbach's alpha for subscales ranged from 0.67 to 0.92; testretest reliabilities ranged from 0.49 to 0.80 with higher reliabilities occurring when time of retest matched time of original testing. Overall EIIC scores correlated to the short Memory-Orientation-Concentration (MOC) test and the Mini-Mental Status Examination (MMSE) at values supporting convergent validity (r = 0.67 and −0.74, respectively). Evidence for divergent validity is a small, negative, nonsignificant correlations (r = −0.15, −0.18) of the EIIC at Times 1 and 2 to the Bradburn Affect Balance Scale. © 1993 John Wiley & Sons, Inc.