Systemic lupus erythematosus (SLE) is a disease which has interested both the investigator and the clinician in recent years. However, relatively little attention has so far been paid to the psychiatric aspects. While these have been mentioned in passing in many of the papers describing this disease, there have been few systematic descriptions of the wide variety of psychotic patterns that can accompany SLE. Psychiatric evaluation has been complicated by the fact that lupus is a disseminated disease which causes cerebral involvement, as well as reactive emotional changes. In addition to the syndromes which can naturally occur with SLE, the differential diagnosis must take into account the iatrogenic effect of treatment with steroids. In this paper we shall suggest a classification of psychotic syndromes and present illustrative case material. The importance of psychiatric evaluation in the medical management of patients will be discussed.