Spontaneous enophthalmos unrelated to trauma or surgery is rare. The term 'silent sinus syndrome' has been used to describe this process where, in particular, there is an absence of any sino-nasal symptoms. The enophthalmos and hypoglobus that occurs in these subjects is caused by atelectasis of the maxillary antrum, which itself appears to be due to chronic maxillary hypoventilation. We report a case of silent sinus syndrome that arose following insertion of a nasogastric tube. Whilst acute paranasal sinusitis is a well-described sequela of nasal intubation, this association with a rare, and as yet unexplained, phenomenon may go some way to explain its aetiology.