Causes for acquired unilateral obstruction of the ureter are numerous: calculi, infections, blood clots and tumors are the most common underlying pathologies. Hematologic tumors with initial clinical manifestation in the lower urinary tract are rare. Primary localization of plasmocytoma has been described in kidney, bladder and urethra. Herein, we describe the first manifestation of a primary solitary extramedullary plasmacytoma of the ureter. The tumor was discovered upon diagnostic workup of gross hematuria and asymptomatic hydronephrosis. Thus far, after radical surgery the patient remains free of disease.