The article contains the description of Foix-Alajouanine syndrome (FAS) from literature. Three our own cases of FAS, which developed in two men and one woman, are presented. An analysis of FAS clinical picture revealed a step-like progression of the disease with a possibility of short-term fluctuation of some focal neurological signs. Five stages of clinical course of FAS were detected. Some peculiar sings of spinal neurovisualization, together with serum and cerebro-spinal fluid (CSF) laboratory examinations, were indicated in FAS. Surgery is first-choice of FAS treatment. Pharmacological treatment with high doses of anticoagulants, together with antiviral therapy (and antibiotics, if necessary), neuroprotectors, antiedematic and symptomatic therapy must be started early. Prevention of thrombotic, trophic and purulent complications is required.