The objective of this project was to determine the prevalence of hyperprolactinemia (HPRL) in systemic lupus erythematosus (SLE) and to evaluate the role of prolactin (PRL) as a disease-activity marker. We determined PRL in a cohort of 182 patients with SLE. Basal prolactin levels and clinical data (disease-activity index, sero-activity, medications) were analyzed in all patients. The findings show only mildly elevated PRL levels in four SLE-patients and normaprolactinemia in 98% (n = 178), without any association with disease activity. Our results differ from previous studies. HPRL appears not to be prevalent in SLE, nor to be associated with disease activity.