Antiphospholipid antibodies, both anticardiolipin antibody and lupus anticoagulant, are associated with a hypercoagulable state, manifested as thrombotic events and pregnancy losses. Multiple coagulation tests are available for the lupus anticoagulant, but few are in wide use. The modified Russell viper venom test (RVVT) is one of several excellent tests for the lupus anticoagulant, with high sensitivity and specificity. We present an automated method for measuring the RVVT and demonstrate its reproducibility.