Acute phosphate nephropathy (APhN) following oral sodium phosphate solution (OSP) ingestion as a bowel purgative has been frequently reported. It was recently suggested that APhN could progress to chronic kidney disease (CKD) and a history of APhN might be considered as one of the causes of CKD. However, there are few reports proving APhN as a cause of CKD. Here, we report a case of APhN that progressed to CKD, as proven by renal biopsy.