This thesis analyzes the current transport situation of Arlanda Airport and the two main cities that Arlanda is located between, Stockholm and Uppsala. The purpose of the thesis is to study the efficiency of the different transport alternatives and also to relate it with their current market shares. Besides, in order to do a deeper analysis of Arlanda Airport connectivity some of the busiest airports transport links have been analyzed in terms of availability of different transport alternatives, distance to the city centers and market shares. Because of the high number of cars that currently go to Arlanda, there is a need to reduce the emissions of carbon dioxide. To this end, a prediction of the demand in ten years has been carried out to see what improvements have to be done to make Arlanda a more environmentally friendly airport. The methodology used in order to forecast the demand has been based on a survey conducted at a single point to regular users of the public transportation system. The improvement of the connectivity of Arlanda Airport via public transport alternatives will not only affect the distribution of the current market shares, but also represents a key strategy for pursuing Arlanda’s leadership in achieving environmental goals.