The cardiac autonomic function was evaluated in 23 patients with Systemic Lupus Erythematosus (SLE) without clinical expression of dysautonomia and in 14 healthy volunteer subjects as a control group, by analysis of Heart Rate Variability (HRV) from 24h ambulatory electrocardiography. All the patients were taking corticosteroids and 10 of them also Ciclosporin A (CsA). The following parameters of HRV were performed: Time domain: standard deviation of the RR intervals average (SDNN) and percentage of RR adjacent intervals differing from each other more than 50 msec (pNN50). Frequency domain: low frequencies (LF) and high frequencies (HF). Significant lower values were detected in SLE patients vs controls: SDNN = 69.40 vs 127.72; pNN50 = 16.44 vs 25.95; LF = 8.34 vs 34.97; HF = 3.21 vs 12.18. The incidence of autonomic dysfunction in our SLE population evaluated by considering intervals of normality is approximately 78% for SDNN; 17% for pNN50; 91% for LF and, finally, 56% for HF. The analysis of HRV may be a valuable technique in the study of the incidence of dysautonomia for these patients.