The fetal environment may be a contributing factor in the etiology of some adult diseases. This study examined whether birth weight, birth length and gestational age are associated with the subsequent development of systemic lupus erythematosus (SLE). The Marshfield Clinic Lupus Registry was searched to identify patients who were born at Saint Joseph’s Hospital in Marshfield, Wisconsin, USA. Birth data on each case and five age-, sex-, and race-matched controls were recorded from medical and delivery room register records. Perinatal data were obtained for 23 cases and 115 controls. The unadjusted mean birth weight was similar for cases (3407 + 581 g) and controls (3422 + 514 g). Birth length was not different between groups. Birth weight adjusted for gestational age, analysed by conditional logistic regression, was not statistically significantly different between groups. We concluded that birth weight and length were similar among SLE cases and controls, suggesting that these perinatal characteristics are not associated with subsequent SLE.