Public transport in the Czech Republic is efficient, relatively safe (see Dangers and Annoyances) and cheap.
From the airport you have a choice of buses to get you to the city centre. Bus number 119 will take you to to Dejvicka (tube line A to the centre). The journey takes approx. 20 minutes and Dejvicka is the terminus, so you can’t miss your stop.
Bus number 100 will take you to Zlicin (tube line B) and Bus AE will take you directly to Nadrazi Holesovice.
There is night bus service 510, which will drop you a Divorka Sarka, where you can catch night tram 51 to the centre. You may find Divorka Sarka a little lonely in the middle of the night esepecially if you are travelling on your own.
Your ticket will cost you 20czk and can be bought at a kiosk at the airport or at the ticket machine at the bus stop, (the ticket machine will only take coins). The ticket kiosk is located to the right of you as you come through arrivals (terminal 1). This kiosk closes around 10.00pm. Tickets can also be bought on the bus for a couple of crowns more. You will need to have change, don’t present the driver with a 1000Kc note, he’ll give short shift.
Buses, trams and tubes run on a trust system in the Czech Republic and when you board the bus you will see little yellow boxes where you can validate your ticket. If you do not have a ticket or have not stamped your ticket you will be fined 500 CZK on the spot if an inspector gets on. The public humiliation is thrown in free. I’ve seen Czech Ticket Inspectors in action and it’s not pretty or an ideal way to start your trip.
Once stamped a 20 CZK ticket is valid for 75 minutes on weekdays and 90 minutes at the weekends and you can hop on and off as many buses, trams and tubes as you want within this time. These tickets are not valid for trains.
The airport bus runs every 10 minutes and the last bus from the airport leaves at 12.00 pm starting again at 4.30am.
As with all public transport in busy cities please take care of your belongings. Pickpockets like Prague too.