Giant salivary gland calculi (GSGC; >15 mm) are considered rare. Only 14 well-documented cases have been reported in the literature since 1942. The purpose of this study was to evaluate the imaging modality and treatment outcome of patients with GSGC.Six personally observed subjects with GSGC were evaluated and treated. Occlusal film, panoramic radiograph, axial computed tomographic (CT) scan, and scintigraphy were used for imaging. Stone location, shape, and size were estimated on occlusal film, panoramic radiograph, and CT scans. Stones were removed with transoral sialolithotomy, and size was measured directly on the surgical specimen. Treatment outcome was evaluated with scintigraphy 2 months after surgery.The mean age of the patients (all male) was 48 years (range, 25 to 61 years). Five subjects had stone in the submandibular gland, and 1 in the parotid gland. The mean stone size was 30 x 15.8 mm, as measured directly on the surgical specimen. The preoperative estimation of the stone size with occlusal film was limited to those located in the anterior portion of the duct. Panoramic radiograph was precise and comparable with the estimation with CT scan for all stones. In 5 of the 6 subjects, a nearly normal function of the glands was seen 2 months after surgery.GSGC of the submandibular or parotid glands is a disease that affects the middle-aged male patient. An occlusal film is a suitable imaging modality for stones, but estimation of size is limited to stones in the anterior duct portion. Panoramic radiograph and CT scan were comparable in precise preoperative estimation of stone size, regardless of stone location. Removal of the GSGC with the minimally invasive method, via the transoral sialolithotomy, is the treatment of choice, with reasonable results.