The diagnosis of IgA-dominant post-infectious glomerulonephritis (PIGN) may be challenging, as it must be differentiated from that of active IgA nephropathy. Predominant clinicopathologic features of IgA-dominant PIGN substantially overlap with those of active IgA nephropathy. Here, we present a case of a 67-year-old woman with rapidly rising serum creatinine, proteinuria and severe hypertension. The kidney biopsy findings included some features of IgA-dominant PIGN while others were more consistent with classical IgA nephropathy. We describe this patient's immune profile at the time of acute kidney injury and review the literature regarding differentiation of the two entities.