All 4 patients with transverse myelitis (TM) included in a prospective study of 500 patients with systemic lupus erythematosus (SLE) tested for anticardiolipin (aCL) antibodies were found to be positive. To determine if the apparently strong association between transverse myelitis and antiphospholipid antibodies (aPLA) in patients with SLE continued to hold, we chose 12 patients with SLE with transverse myelitis from 2 institutions. Eleven of the 12 patients with SLE were tested for aCL and all but one was positive. Most of them (n = 8) had both IgG and IgM isotype aCL. The one who was negative had had a positive VDRL and prolonged APTT 15 months earlier, coinciding with the episode of transverse myelitis. One patient died before she was tested for aCL but she also had a false positive VDRL. Thus, all 12 patients with SLE with transverse myelitis had evidence of aPLA. We conclude that there is strong association between transverse myelitis in SLE and the presence of aPLA.