We report herein an unusual case of systemic lupus erythematosus in a 35-year-old woman who developed acute abdominal pain while hospitalized. Abdominal computed tomography (CT) scan with enhancement indicated long-segment inflammatory lesions in the right ureter. The patient received spasmolytic and analgesic drugs with poor effect and continued to have persistent severe abdominal pain and signs of peritonitis. We suspected that the patient had acute abdominal disease, but no abnormality was detected during laparoscopic surgery. Therefore, we considered the possibility of right upper urinary tract hydronephrosis; the patient's abdominal pain was relieved after double-J tube implantation. The patient's clinical symptoms improved after hormone and mycophenolate mofetil therapy for 1 year, and all laboratory indicators returned to normal. Reexamination by abdominal CT showed that the long-segment inflammatory lesions of the right ureter had resolved. Early identification and diagnosis are important for ureteritis associated with systemic lupus erythematosus.