Gallbladder adenomyomatosis (GADM) is a common acquired benign hyperplastic disease of the gallbladder mucosa with prevalence of 2.8% to 5%. Sonographically it is characterized by diffuse or focal thickening of the gallbladder wall associated with small intramural cystic spaces, known as Rokitansky-Aschoff sinuses. These sinuses may contain tiny echogenic foci that commonly cause a reverberation artifact. We describe and discuss a case of GADM that on color Doppler sonography showed a twinkling artifact. To the best of our knowledge, this finding has not been described previously.