The expression of Fc gamma RI, Fc gamma RII and Fc gamma RIII on granulocytes in the blood of patients with systemic lupus erythematosus was investigated. The relationship between the receptor expression and serum immune complex (IC) concentration was analysed. The decrease in mean fluorescence intensity of both Fc gamma RII and Fc gamma RIII of patients' granulocytes stained by specific monoclonal antibodies (using MoAb IV.3 and 3G8) was significant. The detected decrease of Fc gamma RII was inversely correlated with the high circulating IC level in patients' sera.