This document lists retroperitoneal abdominal organs such as the adrenal glands, aorta, inferior vena cava, parts of the duodenum, pancreas, ureters, parts of the colon, kidneys, esophagus, and parts of the rectum. It provides a mnemonic - SAD PUCKER - to help remember these retroperitoneal organs and notes that some organs like the duodenum, pancreas and colon are secondarily retroperitoneal having developed intraperitoneally and migrated retroperitoneally.