Polyradiculoneuropathy is a rare and potentially severe complication of systemic lupus erythematosus (SLE). Treatment is not codified and response to corticosteroid is inconstant. We report the case of a patient with severe SLE-associated polyradiculoneuropathy and autoimmune thrombocytopenia. Dramatic neurologic improvement and correction of thrombocytopenia were observed after a single course of high-dose intravenous immunoglobulin infusions (IVIg, 2g/kg body weight). Our case suggests that IVIg may be effective in the treatment of this unusual condition.