The retroperitoneal spaceRetroperitoneal space extends from the cranial aspect of the diaphragm to the caudal aspect of the pelvis, containing a diverse array of organs. The posterior parietal peritoneum forms its anterior boundary, while the transversalis fascia defines its posterior limit. At the abdominal level, the retroperitoneal space can be subdivided into perirenalPerirenal, anterior pararenal, and posterior pararenal spaces. These divisions are demarcated by the posterior parietal peritoneum, anterior renal fasciaRenal fascia, posterior renal fasciaPosterior renal fascia, lateroconal fasciaLateroconal fascia, and transversalis fascia. The perirenal space encompasses the kidney and adrenal glands, while the anterior pararenal spaceAnterior pararenal space includes the pancreas, duodenum, and ascending and descending colons. In contrast, the posterior pararenal spacePosterior pararenal space lacks visceral organs and consists solely of fatty tissue. A comprehensive understanding of retroperitoneal anatomy is pivotal for radiologic diagnosis and the interpretation of disease pathways.