Gallbladder adenomyomatosis (GA) is a benign, proliferative condition characterized by gallbladder wall thickening and the presence of Rokitansky-Aschoff sinuses. Though generally asymptomatic, GA can mimic acute cholecystitis, leading to diagnostic challenges. We present a case of a 32-year-old male with a year-long history of recurrent right hypochondriac pain radiating to the shoulder, accompanied by nausea and vomiting. Initial clinical and laboratory findings suggested acute cholecystitis. Imaging studies, including ultrasonography and magnetic resonance cholangiopancreatography, revealed diffuse gallbladder wall thickening with cystic spaces, indicative of adenomyomatosis. The absence of gallstones and the presence of a dilated cystic duct further supported the diagnosis. The patient underwent elective laparoscopic cholecystectomy, and histopathological examination confirmed diffuse adenomyomatosis with smooth muscle hypertrophy and Rokitansky-Aschoff sinuses. The postoperative recovery was uneventful, and the patient remained asymptomatic during a six-month follow-up. Gallbladder adenomyomatosis is benign and can be detected by imaging or during cholecystectomy. Theoretically, adenomyomatosis doesn't need any special care unless it presents symptoms, whether or not cholecystolithiasis is present.