We report a case of diffuse diverticulosis of the gallbladder in a 32 year old patient, who presents epigastric pains and decayed general conditions. With the suspicion of a primitive tumor of the gallbladder, we make a cholecystectomy and the intraoperative histological examination shows a "diffuse diverticulosis of the gallbladder wall"; it displays micro-stones inside diverticulums, too. The patient, after the surgical treatment, has no problem and he gets back to his normal weight. The literature shows the rarity of this disease; its etiopathogenesis is connected with congenital factors. In our opinion, the many terms used (cholecystitis glandularis proliferans, hypertrophic, adenomyomatosis) to define those conditions are not appropriate for our case but rather for the gallbladder's chronic inflammation characterized by the Rokitansky-Ashoff sinuses.