A case of unilateral multicystic renal dysplasia was reported in view of rarity and a review of literatures related to this case was presented. The patient, an 8-month-old Korean female, was admitted to Busan National University Hospital with a complaint of palpable mass on the left flank from birth. Physical examination revealed a well developed, well nourished female. A huge, soft, movable mass in the left flank was palpated. An excretory urogram (I.V.P.) revealed non-visualization of left kidney. No other anomaly was noted. The gross specimen submitted was a product of left nephrectomy with a 2.5㎝ segment of left ureter. The kidney was 15×10×4㎝ in dimensions and 260gm in weight. The lesion was confirmed morphologically to be a congenital multicystic renal dysplasia.