Systemic lupus erythematosus (SLE) is a common connectivetissue disease that involves almost all organ systems. Involvement ofthe brain is one of the most important complications of SLE. About30–70% of SLE patients develop brain involvement, which ismanifested as cerebrovascular disease, seizures, cognitive disorders,headaches, and psychosis.The aim of this study was to investigate whetherneuropsychological dysfunction in SLE was associated alterations inCBF.Total Cerebral Blood Flow Volume (TCBFV) was assessed bymeasuring flow volume of the extra cranial internal carotid andvertebral arteries using Doppler Ultrasonography andneuropsychological status was assessed by the Mini-Mental StateExamination (MMSE), Modified Mini-Mental State Examination(3MS), and Ceneral health Questionaire (GHQ) in 21 SLE patientssubgrouped into 10 patients with Atiphpospholipid Syndrome (GroupIa) and 11 patients without Atiphospholipid Syndrome (Group Ib) and10 healthy volunteers.It was found that CBFV in the Left ICA was significantly lowerin patients than in controls (p value=0.05).It was also found thatTCBFV was significantly lower in patients with SLE diseses activity(p value=0.006).There was no significant difference between patientsand controls regarding MMSE, 3MS, or GHQ.There was nosignificant difference between patient subgroups regarding TCBFV,MMSE, 3MS, or GHQ.In conclusion, cerebral hypoperfusion measured by Dopplerultrasonography was detected in patients with SLE and is related todisease activity.