Stenosing ureteritis (SU), a rare complication of Henoch–Schönlein purpura (HSP), typically presents with severe symptoms. We report the cases of two HSP patients presenting with gross hematuria, blood clotting, and colicky flank pain, followed by purpura on the lower extremities. Early-stage ultrasonography indicated hydronephrosis, thickened renal pelvic mucous membrane, and ureteral dilatation (UD), suggesting HSP complicated with SU. After early SU treatment with prednisolone, kidney function, thickened renal pelvic mucous membrane, and UD progressively normalized and the pain gradually disappeared. Regular ultrasonography of HSP patients from the onset of gross hematuria can be useful to detect early SU and facilitate conservative therapy with prednisolone. Diagnosis of SU can be easily missed by assuming HSP nephritis, particularly owing to the non-specific symptoms. Common characteristics as well as treatment methods and prognosis of SU are given in the literature review.