A 43-year-old woman who had been diagnosed as primary Sjögren's syndrome since 1986 developed severe constipation, urinary retention, dizziness at standing and polyarthralgia in February, 1990. Laboratory tests revealed proteinuria, hypocomplementemia and high titer of anti-DNA antibody. Diagnosis of SLE was made and she was admitted to our hospital on April 2, 1990. Physical examination on admission showed that she also had asymmetric pupils, impairment of sweating, orthostatic hypotension, neurogenic bladder, gastro-intestinal dysmotility and the diminution of R-R interval variability during deep breathing on the electrocardiogram. These findings suggested that she had pan-dysautonomia but there were no signs of motor and sensory disturbance. Because other diseases such as diabetes mellitus and amyloidosis which induced dysautonomia could be ruled out, her pan-dysautonomia seemed to be due to SLE. After the treatment with steroid pulse therapy, most of her dysautonomia improved rapidly. However, some of the disturbance had persisted for a long time. Pan-dysautonomia has been rarely reported as a complication of SLE, and high dose of steroid therapy at the early stage should be considered.