Cystitis related with systemic lupus erythematosis (SLE) is termed as lupus cystitis. It is a subtype of SLE in which gastrointestinal and bladder symptoms are prominent and it usually manifests with other symptoms of SLE. We present a case in a 37-year-old woman whose sole complaint was the severe urinary symptoms. A biopsy of the bladder showed inflammation in the submucosa and the finding of vasculitis. An autoimmune disease was suspected from the blood serum sample. A further laboratory study was performed and she was diagnosed with SLE and lupus cystitis. Prompt therapy with corticosteroids resulted in the improvement of the severe bladder symptoms.