In Alzheimer’s disease (AD), association of cognition with disease biomarkers is important for accurate diagnosis, prognosis and staging. We studied the value of cerebrospinal fluid (CSF), cortical thickness (CT), and volume (V) measures (in isolation & combination) to predict cognitive ability, as well as cognitive status, in a cross-sectional study of data from Alzheimer’s Disease Neuroimaging Initiative (ADNI). Cognitive status was measured by Mini Mental State Exam (MMSE). Results show that combining biomarkers allows more accurate AD diagnosis. Specifically, combining CSF, CT, and V measures seems promising. In isolation, CSF levels show significant but weak associations with MMSE. Aβ 1– 42 is associated with Mild Cognitive Impairment. CT and V measures of hippocampus and entorhinal cortex are strongly associated with Alzheimer ‘s Disease diagnosis and with ruling out the disease.