Neuropsychiatric manifestations are commonly observed in systemic lupus erythematosus (SLE) patients. In particular, neurological involvement is known to be more common in patients with positive anticardiolipin antibodies and lupus anticoagulants. Nevertheless, cerebellar ataxia has rarely been reported, especially as the first clinical manifestation of this systemic autoimmune disorder. Cerebral vascular infarction or ischemia, vasogenic oedema and antibody-mediated cerebral vasculopathy or vasculitic process have been supposed as possible aetiologies of acute cerebellar ataxia related to SLE. We report the clinical and radiological features of a woman who developed a rapidly progressive cerebellar syndrome as first sign of SLE; no other cause explaining her cerebellar ataxia was found. The patient improved after high-dose steroids. The appearance of a cerebellar syndrome with unknown aetiology with associated features of possible systemic autoimmune dysfunction, should be taken into account in clinical practice for appropriate diagnostic workup in order to provide effective therapeutic options.