Behcet's disease (BD) is a chronic, multisystemic disorder with variable prevalence in different geographical areas. Neurological manifestations (neuro-Behcet's disease, NBD) are well recognized. We studied 40 Iraqi patients with NBD from a neurological unit in a large teaching hospital, all fulfilling the International Study group criteria for the diagnosis of BD. There were 37 males and three females. Thirty-nine were Arab Muslims and one was a Kurd Muslim. Mean age at neurological presentation was 29+/-7.6 years (range 18-50 years). Fifteen out of 23 tested patients (65%) had a positive pathergy test and seven out of 13 tested (54%) had HLA-B5(51). A classification into three reasonably clear distinctive main patterns of neurological presentation is proposed. First: a parenchymal CNS pattern (the commonest) - 26 patients (65%), which included three relatively common forms: brain stem syndrome (10 patients), diffuse form (predominantly with pseudobulbar signs) (nine patients) and cerebral stroke-like form (five patients); and two less common forms: psychiatric and myelopathy (one patient each). Second: intracranial hypertension (IH) (with papilledema) - 11 patients (27.5%). Third: meningitis-like pattern - three patients (7. 5%). This classification has clinical, etiopathological, therapeutic and prognostic implications. In conclusion, NBD is not uncommon in Iraq, and it affects predominately Arab Muslims. BD should be routinely looked for in adult patient, especially males, in their third and fourth decades who present with IH and papilledema, brain stem syndrome, pseudobulbar palsy, stroke, meningitis or myelopathy.