Drug smuggling is the illegal transportation of prohibited narcotics from one country to another in violation of customs legislation. It is widespread because of the huge profits being made. There are a large variety of modes of smuggling. Individual carriers, including transportation personnel, tourists, businessmen, diplomats and plain criminals carry relatively small amounts as they travel. Drugs are disguised as legitimate goods and shipped through legitimate means of transportation. Boat loads and plane loads of drugs are smuggled into little used landing spots. The major contemporary drugs being smuggled are marijuana, heroin and cocaine

It is likely that the greatest value of drug smuggling is between South America and the USA. Other major routes are from the Middle East and Southeast Asia to Europe and the USA. Most heroin is produced in Southeast Asia, with west Asia and Central America producing the bulk of the rest. It is shipped to Europe, Australia and North America with the largest part going to the USA. Cocaine is produced in Colombia, Peru and Bolivia and shipped to Europe and North America. The largest producer of marijuana is the USA where most of it is consumed. It has been estimated that the annual drugs business is worth $300 billion to the world banking system, namely as much as oil. These illicit substances are now only exceeded by armaments in total value as an internationally traded commodity