The prognosis of patients with allograft IgA nephropathy (IgAN) requires further investigation. We performed a bicenter retrospective cohort study on kidney transplant recipients diagnosed with IgAN in allograft biopsy. Recipients without allograft IgAN but with known IgAN before transplantation were included as the control group. We investigated the associations between clinicopathological characteristics, including allograft crescents, and the risk of death-censored graft failure. In total, 1256 IgAN patients in both pre- and posttransplant stages were included. Among them, 559 were diagnosed with allograft IgAN, which was a time-dependent risk factor for worse prognosis (adjusted hazard ratio = 5.009 [3.610-6.951]; P < .001) during a median of 8.1 years of follow-up. Of the patients with allograft IgAN, 88 (15.9%) had glomerular crescents, including 40 patients (7.2%) with >10% crescent formation in the total biopsied glomeruli. The presence of glomerular crescents in IgAN was associated with a worse graft prognosis, and the association was still valid with the C scores of the current Oxford classification. In conclusion, allograft IgAN is a time-dependent event and is associated with worse graft outcomes. The pathological characteristics of allograft, particularly the degree of glomerular crescent formation, may represent important risk factors for a poor prognosis.