Introduction: Non‐Hodgkin's lymphomas are a heterogeneous group of malignancies in the lymphoid system and ureteric involvement by non‐Hodgkin's lymphoma is very rare.Case presentation: We present a 37‐year‐old male, presenting with lower urinary tract symptoms and right flank pain. Initially, he presented with lower urinary tract symptoms without having any evidence of urinary tract infection and was managed for nonspecific cystitis. His ureteral histopathology report indicated a diffused infiltration by malignant lymphoid cells and the final diagnosis revealed diffuse large B‐cell lymphoma. His positron‐emission tomography scan indicated stage 4 disease with skeletal involvement and he was then treated by rituximab, cyclophosphamide, liposomal doxorubicin, vincristine, and methylprednisolone chemotherapy. Later, he was also diagnosed with central nervous system lymphoma and died during his stay in the hospital.Conclusion: Primary diffuse large B‐cell lymphoma of the ureter is extremely rare; however, it should be considered in the differential diagnosis for patients presenting with obstructive uropathy as its early detection is crucial for diagnostic and therapeutic treatment.