The Neurosyphilis is the most severe neurological complication of the active syphilis. It puts real diagnostic problems because of the ascendancy of the atypical forms. Our objective is to analyze the clinical symptoms and to assess the relevance of the different laboratory findings in cerebrospinal fluid (CSF) and serum for the diagnosis and survey of active neurosyphilis. A retrospective study of six hospitalized neurosyphilitic patients at Hospital Moulay Ismail of Meknès from 2003 to 2015 was carried out. Neurosyphilis can be grouped in two categories: early (meningeal and meningovascular neurosyphilis) and late (progressive general paralysis and tabes dorsalis). All patients are HIV negative. All the patients are benefited for an examination cytochimique of the CSF and an examination immunological with the tests VDRL and TPHA for the search for the specific antibodies in the CFS and the serum. The CSF anomalies in neurosyphilis included elevated cell count with lymphocytic-plasmocytic cell reaction, increased protein content, strongly positive blood and CSF serology.