The occurrence of ataxic sensory neuronopathy (ASN) is rare in patients with connective tissue diseases (CTDs). ASN has been described in case reports and case series in patients with CTDs, mostly Sjögren's syndrome, and most often occurring during middle or old age. ASN in association with systemic lupus erythematosus (SLE) is extremely rare; there has been only one reported case in the literature. In addition, to our knowledge, adolescent onset of symptoms in CTD-associated ASN has not been reported previously. We report the case of a young woman who presented with ASN, characterized by sensory ataxia, with elevated antinuclear antibodies, leukopenia and anemia; she fulfilled the diagnostic criteria for SLE about 7 years after the onset of sensory ataxia. Our case points out that ASN may be the initial presenting feature of SLE. SLE should be included in the differential diagnosis of ASN, especially in patients of young age.