Acute unilateral parotid gland swelling after general anesthesia, anesthesia mumps is rare and when occurred, it is associated with the patient's position and with long-lasting surgery. The exact mechanism or etiology has not been fully established but stasis of gland secretion, blockage of Stensen's duct by direct compression, or retrograde flow of air by increased the oral cavity pressure are suspicious reasons. We experienced a case of soft tissue swelling in the left preauricular and submandibular regions in a 40-year-old female patient after short-lasting, hysteroscopic myomectomy performed in the lithotomy position with no suspicious predisposing factor. It is required to pay attention on the fact that even with the usual face mask ventilation can lead to the development of anesthesia mumps.