A 6-year-old female presented with right hemichorea, initially thought to be post-streptococcal, which subsequently progressed to a right dystonic hemiplegia. At 7½ years she developed right focal and secondary generalized tonic–clonic seizures. These became intractable. A brain biopsy was consistent with Rasmussen's encephalitis (RE). At 9½ years the child underwent a left hemispherectomy making a good recovery with resolution of seizures. At 12 years she presented with recurrent episodes of abdominal pain, fever, and malar rash with serological evidence of systemic lupus erythematosus (SLE). A possible link between RE and SLE is discussed.