Renal abscess is a rare disease in newborn, but severe consequences can occur: sepsis with high mortality, renal scar formation and risk of chronic renal failure. A neonate with unilateral renal abscess due to Staphylococcus aureus is reported, with septicemia, with no other suppurative focus, nor with urinary malformation, with good clinical evolution with intravenous antibiotics and without surgical treatment, but with renal scars sequel. From this case, the strategies of diagnosis, treatment and followup of the renal abscess in a neonate are analyzed, emphasizing the early diagnosis to avoid renal scars.