BIN1, as an important genetic susceptibility locus in late-onset Alzheimer's disease (AD), is overexpressed in AD brains. Our study investigated BIN1 diagnostic value by quantifying its transcription level and plasma expression from 112 AD and 200 control subjects. We observed significant increase in BIN1 mRNA and protein levels in AD patients. Receiver operating characteristic curve analysis shown the sensitivity and specificity were 73% and 75% for plasma BIN1 in identifying AD. Although this is a pilot study requiring corroboration on a larger cohort of patients, our results highlight the possible use of plasma BIN1 as a biomarker for AD diagnosis.