INTRODUCTION: Acute parotid gland enlargement is an extremely rare post-surgical complication. Several etiological factors have been proposed, including preoperative dehydration, medications that cause an increase in viscosity of glandular secretions or loss of muscle tone and retrograde passage of air into the parotid glands, prolonged surgery, and operative position of the patient leading to pooling of secretions of the gland. CASE REPRESENTATION: We present a series of two cases that developed bilateral enlargement of parotid glands post-operatively. Case 1 was a 30-year-old male who underwent a Trendelenburg operation with flush ligation and ligation of perforators for varicose veins of the right leg under spinal anaesthesia with bupivacaine. Fentanyl, midazolam, bupivacaine, and ondansetron were administered to the patient perioperatively. Case 2 was a 51-year-old female who underwent laparoscopic cholecystectomy for cholelithiasis under general anaesthesia. Fentanyl, midazolam, sevoflurane, and vecuronium were administered to this patient during the surgery. Both of these cases were managed conservatively by adequate hydration, antibiotics, and analgesics, and they recovered completely three days following the surgery. CONCLUSION: The causative drug could not be well-established, but such cases stress that the surgeon, anesthetist, and patients should be aware of possibility of this adverse event. Postoperative anaesthesia mumps are usually of minimal clinical significance and resolve spontaneously with appropriate symptomatic care.