The abdominal sympathetic nervous system provides sympathetic innervation to the abdominal organs and gonads. This system is part of an extensive neural network that extends from the base of the skull to the pelvis. The preaortic (or prevertebral) plexus is a key component of the abdominal sympathetic system and is represented by a variable nervous network located anterior to the abdominal aorta. The aim of our study was to identify all these sympathetic structures and describe the formation and relationships of the preaortic plexus. We examined five cadavers (aged 66–71) with no medical or surgical history, preserved in 9% formalin at the Anatomy Department from Carol Davila University. Regional dissections were performed in successive planes, highlighting the major abdominal plexuses, the lumbar splanchnic nerves, and the associated network of neural connections that contribute to the preaortic plexus. The plexus is formed by efferent fibers from the celiac and aortico-renal ganglia, as well as from the three lumbar splanchnic nerves. The lumbar splanchnic nerves originate in the paravertebral sympathetic chains. We identified all these sympathetic structures and described the formation and anatomical relationships of the plexus. The nerve fibers of various origins form a longitudinally oriented network located anterolateral to the abdominal aorta. The lower part of this network continues into the superior hypogastric plexus. This neural network is delicate, complex, and variable, making it challenging to identify anatomically and surgically. Situated deeply in the retroperitoneal space, it is prone to accidental injuries during surgery in this compartment.