Khat leaves are cultivated in the highlands of the Horn of Africa, Southern Arabia and along the East African coast. In many countries, chewing khat is an age-old tradition. More recently, the mass migration of people from the Horn of Africa has been associated with the spread of khat usage to neighbouring countries, Europe and the rest of the world. Exact numbers of regular khat users on a worldwide scale do not exist, however estimates range up to 20 million. This paper presents the challenges associated with the spread of khat consumption.