Peri-orbital subcutaneous emphysema is a rare complication of functional endoscopic sinus surgery (FESS). In most cases, it resolves spontaneously without any sequalae. However, it can progress rapidly to irreversible blindness. We present two cases of peri-orbital subcutaneous emphysema, occurring as a complication of FESS, causing transient orbital proptosis. The first occurred following a Draf IIa full house FESS in a patient with an in-tact lamina papyracea. The second case is linked to frontal sinus trephination performed as an adjunct to FESS and is the first documented case of surgical emphysema from frontal trephination in a patient with an intact lamina papyracea. Both cases were precipitated by the patient sneezing in the post-operative recovery bay. The patients were observed as inpatients and recovered spontaneously. These cases are unique in having intact lamina papyracea on post-operative CT imaging. This report increases awareness of the complications of FESS and highlights the importance of post-operative observation. Knowledge of the complications of sinus surgery is important for best informing patients and fostering informed consent.