Chewing of Catha edulis, also known as khat or qat, is a widely practised habit in the Arabian Peninsula, East Africa and among immigrants from these regions to Western countries. The habit involves chewing fresh khat leaves, typically on one side of the mouth, and holding the bolus for several hours each day. Long-term khat chewing is believed to be associated with a range of systemic health issues, including cardiovascular diseases, gastrointestinal disorders, liver disease and mental health problems. Additionally, khat chewing has been reported to have detrimental effects on both soft and hard oral tissues, including periodontal diseases, mucosal keratotic lesions, plasma cell stomatitis, tooth discolouration, tooth loss, taste impairment, xerostomia and temporomandibular joint (TMJ) disorders. Meanwhile, the relationship between khat chewing and oral cancer remains controversial, with no conclusive evidence available to date. The prevalence of khat chewing has risen globally, mainly due to the migration of people from khat-producing countries. Consequently, oral and paraoral lesions or conditions that may be induced by habitual khat use are likely to be encountered worldwide. Therefore, dental practitioners, students and interns worldwide need to be aware of this habit and its potential impact on oral health. This chapter highlights the epidemiology of khat chewing and its oral and dental consequences.