Sialolithiasis is one of the most common diseases involving the salivary glands. It is a condition that occurs due to an obstruction in a salivary gland or its duct due to a calculus. The formation of a salivary stone is believed to be secondary to the deposition of mineral salts around a nidus, which is frequently associated with a recurrent bacterial infection. Patients with submandibular sialolithiasis usually present with acute swelling over the neck associated with pain, fever, and purulent intraoral discharge. The size of the calculus varies from <1 mm to a few centimeters. The frequency of sialolithiasis is relatively common. It is estimated to affect 12 in 1000 of the adult population. However, the occurrence of giant sialoliths, >15 mm in any diameter, is rare. Here, we describe our experience with a case of giant submandibular sialolithiasis measuring 25 mm presenting as a painless submandibular mass. The patient underwent submandibular gland excision followed by a full recovery.