Principal characteristics of "aberrant papillae" are described, this curious embryologic anomaly being generally detected from the hematuria provoked. Intravenous urography reveals the presence of a persistent lacuna in a calix or of the pelvis, radiologic evidence of the abnormal papilla. Ultrasound and CT scan imaging provide few supplementary data. The most frequent differential diagnosis is from a pyelocaliceal tumor, the known risk of evolutory changes in the latter explaining why most "aberrant papillae" are treated by nephrectomy or even nephroureterectomy. The use of nephroscopy or ureteroscopy should allow, as in the case reported, these abusive nephrectomies to be avoided in the future.