The heat shock proteins are a group of evolutionarily conserved proteins with important physiological functions, whose synthesis is enhanced by elevated temperature or other stresses. A role for one or more of these proteins in human autoimmune disease has been extensively discussed. This review considers the evidence of a role for hsp90 in systemic lupus erythematosus (SLE) where over-expression of this protein, its surface localization and auto-antibodies to it have been observed in both human patients and in the MRL/1pr mouse model of SLE.