Acute oxalate nephropathy is a rare but important cause of severe acute kidney injury. We report here two cases presenting as unexplained AKI which were confirmed histologically to be due to acute oxalate nephropathy. Dietary oxalate or its precursor vitamin C was the cause of oxalate exposure in both of these cases. While one patient recovered, another continued to need dialysis and succumbed to underlying metastatic cancer. This cause should be suspected in all patients presenting with unexplained AKI, and detailed history about dietary intake of oxalate or vitamin C should be inquired.