Ultrasound imaging plays a crucial role in the assessment of the renal tract in neonates, offering a non-invasive, safe, and effective diagnostic tool for identifying congenital anomalies, parenchymal diseases, and other renal pathologies. This chapter provides a comprehensive overview of the principles, techniques, and clinical applications of neonatal renal ultrasound. Key topics include the anatomical features of the neonatal renal system, optimal imaging techniques, and the interpretation of common findings such as hydronephrosis, renal dysplasia, and pelvic dilatation. Emphasis is placed on the importance of early detection and the role of ultrasound in guiding management decisions. The chapter also discusses the challenges and limitations of neonatal renal ultrasound, including the technical aspects of imaging in small, often premature, patients and the need for follow-up imaging. By providing a detailed guide to renal ultrasound in this sensitive patient population, this chapter aims to enhance clinical practice, improve early diagnosis, and contribute to optimal outcomes in neonatal renal health.