Almost from the beginning of existence of the air transport, air carriers have noticed that frequently although all the seats on a flight were bought, many passengers have not appeared on an airport for the check-in. These passengers are called no-shows. Due to that fact the space on aircrafts was not fully used, carriers has realized that they could gain additional profit from saling more tickets than there were actually seats on an airplane. This practice is called overbooking. Throughout the years the legislators has noticed that many carriers abused the passenger's rights because of the overbooking. Carriers has been saling more tickets than the amount of seats on an aircraft, what often (when the amount of no-shows was lower than the surplus of sold tickets) resulted in the fact that passengers who has purchased tickets were denied the entrance to aircrafts. For that reason, American administration as the first one in the world in 1967 has imposed on carriers legal responsibilities connected with overbooking such as the right for compensation, the procedure and order of proposing the passengers to resign from the flight in exchange of compensation and tickets for the next available flight or additional duties like offering the passengers a possibility to contact their relatives. Shortly afterwords, the legislation of other countries has followed. These legal responsibilities differs from each other depending on the regions and countries. What is the most important factor is whether a country is a developed or developing one. In developed countries usually the protection of passengers rights is high and there are procedures of receiving aid and lump sums in case of denying access to an airplane. Passengers in developing countries are in a substantially worse situation, although the legislation is different in each country. Although the practice of overbooking is very controversial and every once in a while there is a situation which contributes to a heated public debate whether this practice should be completely delegalized, almost everybody benefits from its existence. Carriers because they can gain additional profit, passengers because tickets prices are lower, countries and airports because the space on aircrafts is used more efficiently what results in a smaller amount of flights and less crowded airspace what is also beneficial for our environment. However, we should not forget about passengers that could not get to their destinations what may be for them the reason for personal problems and thus the legislators should guarantee the legal protection for the passengers.