ABSTRACT Diphtheria is an acute, highly infectious, toxigenic, and vaccine-preventable disease that commonly affects children under 12 years of age. We report a 45-year-old gentleman presented to the otorhinolaryngology department, complaining hypernasal speech and nasal regurgitation while eating during follow up post diphtheria infection. He has no underlying illness and claimed completed immunization. In fiber-optics evaluation velopharyngeal insufficiency circumferential pattern was found with normal laryngeal activity.The cause remains undetermined but infectious disease such as diphtheria may play a role in our case. Hence this patient was treated with proton pump inhibitors and referred to speech therapist. After one month follow up, the disease was completely cured and fiber-optics evaluation shows normal velopharyngeal isthmus functions.