A gallbladder polyp of 15 millimeters may be serious and cholecystectomy is recommended to avoid cancerous changes. It is generally accepted that up to 0.5 cm in diameter is often a benign lesion, and above 1.0 cm, it may be an adenomatous polyp or have malignant changes. A gallbladder polyp of 15 millimeters may be or have been cancerous and surgery is recommended as soon as possible. Generally, the probability of cancer is low if the gallbladder polyp is less than 10 millimeters, but if it is more than 10 millimeters, the chance of cancer will increase exponentially. The malignancy of gallbladder cancer is extremely high, and if gallbladder cancer occurs, especially in middle and advanced stages, the terminal survival time of patients is no more than 1 year. Therefore, patients are advised to go to the hospital for examination and clear diagnosis, and then complete the treatment as soon as possible under the guidance of doctors.