The nearest town to reach Champasak is Pakse. The best way to reach Pakse is by bus. Regular buses and minivans are available from cities like Luang Prabang, Vientiane and Vang Vieng, which takes between 8 to 10 hours. There are 4 bus stations in Pakse, which connects the town with other smaller cities too.
The bus ticket varies between 20 to 30 USD per person depending on the city of departure. You can also get there by renting a taxi for about 200 USD. There are flights to Pakse from Vientiane, Bangkok, Siem Reap and Luan Prabang.
From Pakse, there are minivans to Champasak, which can be booked through your hotel or via tour operators (both cost the same), for about 20000 LAK. Buses and minivans are available between 9 to 11 AM every day.