Describes the case of a 28-yr-old male patient with systemic lupus erythematosus whose disease presented as psychosis. The S presented with dysphoric symptoms and he was shifting from anxiety to depression to agitation. He attributed his condition to prolonged dissatisfaction with his job as an accountant. Treatment consisted of a small dose of thioridazine. A few mo later he became overtly psychotic with persecutory delusions. Haloperidol and procyclidine were administered orally with good response. About 8 mo later he relapsed into the same clinical picture and consequently lost his job. Following penfluridol (20 mg) once a week, he became well and resumed work. The S later presented with chest pain and joint pains. Upon admission to the hospital he was found to have pericarditis and was diagnosed with systemic lupus erythematosus. Treatment with prednisolone (60 mg), immuran (160mg), chloroquine (100 mg), and warfarin was begun and psychological symptoms disappeared and did not return. Questions regarding whether the disease was drug induced and whether the psychosis is part of the lupus are discussed.