This case report describes the findings of a 45-year-old white woman from Brazil, who developed myalgia, fever and macular rash. She was diagnosed as having dengue, based on clinical manifestations and specific IgM titers. One week after the first symptoms of dengue, the patient developed muscle weakness, followed by tetraplegia with areflexia, and respiratory insufficiency. The electromyography had evidence of demyelinating neuropathy and the cerebrospinal fluid showed albuminocytologic dissociation. These neurologic findings were consistent with the diagnosis of Guillain-Barré syndrome. The patient was treated with immunoglobulin and metylprednisolone. Mechanical ventilation was started one week after hospital admission and maintained for four weeks. After six weeks of hospitalization the patient was discharged from the hospital on wheel chair, presenting mild muscle weakness and loss of patellar and ankle reflexes. When the patient was seen at the outpatient service three weeks after hospital discharge she was able to walk with help. This case report suggests a possible association between dengue and Guillain-Barré syndrome.