From Prague airport (which is about 90 kilometers away from Pilsen) and which connects to many countries in Europe as well as from outside Europe, you can reach this city of the Czech Republic by car or by using other means of transportation: namely bus or train.
If you prefer to travel by train, connections from Germany directly open the doors to Pilsen.
From other destinations as France, the Netherlands, etc. you can connect by some of the international bus lines.
For more information on transport visit: http://jizdnirady.idnes.cz/vlakyautobusymhdvse/spojeni/