Cortical lesion patients were tested on the Cognitive Assessment System (CAS) in the post-acute phase (median≥1 month) to determine the degree of sensitivity and specificity of the CAS subtests to neuropsychological impairment. Nonparametric ANOVA and subsequent Mann–Whitney statistics were used. Demographic variables of age, education, handedness, sex were controlled for Matching Numbers was sensitive to right-hemisphere lesions while Verbal–Spatial Relations was sensitive to anterior lesions. Receptive Attention and Figure Memory were sensitive to posterior lesions. Number Detection was sensitive to right anterior lesions. Nonverbal Matrices was sensitive right anterior lesions and the inclusion of a disproportionate number of left-handers within this specific group appeared to be partly moderating this effect. The magnitudes of the performance decrement for these subtests were substantial with Figure Memory demonstrating the largest effect. The results suggest that select CAS subtests could be useful for the multiple baseline assessment of neuropsychological functioning.