Neuropsychiatric manifestations are not rarely associated with systemic lupus erythematosus (SLE). Magnetic resonance angiography and positron emission tomography can provide excellent images of cerebral perfusion and metabolism whereas information is still lacking on a possible diagnostic role of ultrasound. In this study we aim to assess whether duplex sonography of neck and intracranial vessels may be useful in distinguishing patients with and without neuropsychiatric SLE (NPSLE). Neck and transcranial duplex sonography was performed by a single operator on 33 women affected by SLE (mean age +/- SD: 47.69+/-8.17 years) and on 15 healthy control subjects. Nineteen patients presented NPSLE. Pulsatility and resistivity indices (PI and RI) were automatically calculated by the ultrasound instrument in internal carotid (ICA) and middle cerebral artery (MCA), on both sides, according to standard methods. No significant haemodynamic differences were found in mean and median PI and RI values of ICA and MCA comparing SLE with NPSLE patients and with healthy control subjects. No correlation was found between MCA and ICA parameters in the same group of patients. Duplex sonography of cerebral vessels is unable to distinguish SLE and NPSLE patients. Heterogeneity of causes in the pathogenesis of NPSLE and the different vascular adaptation of cerebral macrocirculation as opposed to cerebral microcirculation may represent possible reasons that explain the inability of ultrasound to differentiate SLE patients from NPSLE patients.