GOAL: To describe clinical and laboratory features of human immunodeficiency infection (HIV)-infected patients with neurosyphilis. STUDY DESIGN: Retrospective study of 27 consecutive cases of HIV-infected patients with a positive Venereal Disease Research Laboratory (VDRL) in cerebrospinal fluid (CSF). RESULTS: Median of age was 36 years and 89% were men. Ten (37%) patients had previous nonneurologic syphilis treatment. At the time of neurosyphilis diagnosis, 10 (37%) patients had early syphilis, and 6 of them were neurologically asymptomatic. Nine (33%) patients had symptomatic neurosyphilis. Twenty-six (96%) patients were classified with early neurosyphilis. The medians of serum VDRL and CD4 T cell counts were 1:128 and 182 cell/μL, respectively. Twenty five (93%) patients presented serum VDRL titers ≥1:16. Five of 6 patients with early syphilis and asymptomatic neurosyphilis, presented serum VDRL ≥1:16. Symptomatic patients showed lower CD4 T cell counts (59 cell/μL vs. 208 cell/μL, P = 0.03) and higher protein concentration on CSF (118 mg/dL vs. 39 mg/dL, P <0.001) than asymptomatic patients. CONCLUSIONS: Most patients had early and asymptomatic neurosyphilis, and more than one third had early syphilis. Patients with symptomatic neurosyphilis showed lower CD4 T cell counts and higher protein concentration on CSF than those asymptomatic. Most patients had serum VDRL titers ≥1:16, regardless of syphilis stage. © Copyright 2008 American Sexually Transmitted Diseases Association.