The value of blood screening for syphilis and cerebrospinal fluid (CSF) screening for neurosyphilis in acute psychiatric admissions is assessed. Of 1,296 patients, 248 (19%) had evidence of previous or current syphilis as shown by a positive Treponema pallidum haemagglutination test, and 68 (5.2%) had potentially treatable syphilis as shown by a positive Venereal Disease Research Laboratory (VDRL) titre. CSF examination was performed on 169 patients with a positive blood test. Seventeen (i.e. 1.3% of all patients included in the study) met our criteria for neurosyphilis. The best predictor for neurosyphilis was the presence of a reactive serum VDRL. However, it is recommended that all patients with a positive blood test and symptoms that could possibly be ascribed to neurosyphilis undergo CSF examination.