Cerebrospinal fluid norepinephrine (NE) levels were determined by radioenzymatic assay in 21 patients with a variety of neurological diseases and 49 patients in acute alcohol withdrawal. A second determination was made in 19 patients who had recovered from the alcohol withdrawal syndrome. Cerebrospinal fluid NE concentration was higher in the patients during alcohol withdrawal (192.3 plus or minus 22.3 pg/mL) and decreased during recovery to 137.8 plus or minus 15.9 pg/mL. The CSF NE level was higher in both groups than in patients with other neurological disorders. This may help explain the adrenergic signs observed during alcohol withdrawal.