Granulomatosis with polyangiitis (GPA, formerly Wegener's granulomatosis) is a systemic necrotizing vasculitis of small- and medium-sized blood vessels, primarily affecting the upper and lower respiratory tracts, as well as the kidneys. Urogenital manifestations of GPA are exceedingly rare and usually respond well to systemic immunosuppressive therapy. Here, we present a case of a 36-year-old female presenting with acute urinary obstruction secondary to urethral GPA involvement in the immediate postpartum period. Special consideration should be given to ruling out malignancy in all patients with a history of GPA and urethral lesions, especially when there is a history of cyclophosphamide treatment.