The present work describes the surgical treatment of a rare case of tubular duplication of the third duodenum in a 62 y.o. woman come to our attention for acute cholecystitis. It was an accidental diagnosis during diagnostic work-up for another disease. It is a singular and interesting case, mostly for its rarity and for the modality of its presentation. Great importance has been given to the iconography of the diagnostic work up and of the surgical steps of the operation, approached in a totally laparoscopic way. The minimally invasive approach, according to the most recent and innovative standards, has given to the patient a faster and a more comfortable post operative recovery.