Background: some investigators studied the relation between small vessel disease and cognitive functions and they found that, patients with small vessel disease performed more poorly than healthy subjects in some cognitive tests. Objectives: The aim of the study is to assess the relationship between MRI finding of two types of small vessel disease(Isolated lacunar infarction and ischemic leukoariosis) and their risk factor with the neuropsychological tests performance. Methods: forty subjects with MRI assessed cerebral small vessel disease grades on Fazeka's scale between 0-2 and ten healthy control subjects were included in the present study . all subjects were subjected to : complete neurovascular examination, laboratory investigations, MRI brain, ECG, echocardiography and cognitive assessment using tests for global and specific cognitive functions Results : In comparison to the control group, subjects with small vessel disease had significantly lower levels of performance in tests of memory, language, executive functions, verbal fluency and visuospatial function, independent to MRI finding. Isolated lacunar infarction were more prevalent than ischemic leukoariosis in the patient group also a significant correlation between risk factors ( hypertension and diabetes mellitus ) of small vessel disease and its duration of illness and performance in tests of global and specific cognitive functions. Conclusion : Two aspects of (ILI and ILA) of small vessel disease are susceptible to cognitive impairment especially in visuospatial function ,verbal memory, language skills and executive functions.