We report a 40 years old woman with chronic urticaria and acute transverse myelitis associated with systemic lupus erythematosus. The urticaria appeared in her adolescence and after 26 years was followed by photosensitivity, peripheral polyarthritis and acute transverse myelitis, with positive antiphospholipid and antinuclear antibodies. Both chronic urticaria and acute transverse myelitis have been described associated with or appearing as the first manifestation of systemic lupus erythematosus. Transverse myelitis is a rare and still poorly understood condition reported in about 2% of patients with systemic lupus (Rev Méd Chile 2005; 133: 209-13)