Banlung has an airfield within the town, but all commercial airlines have stopped servicing Ratanakiri. The only flights were with Mission Aviation Fellowship, in an 8 seater, but these stopped at the end of 2009. Medivacs and charters are available from Helicopters Cambodia. Currently the Ban Lung runway is still a gravel strip, but there are plans to extend it and build a concrete runway, which would make it more likely to attract a new carrier and make cancellations in the wet season less frequent.
The road between Phnom Penh to Banlung - Rattanakiri is fully paved road and in good in year 2017.
It is possible to get buses to Banlung from/to:
You can book a Bus Ticket online in advance for a few.
A more expensive option than bus, taking a private taxi from Phnom Penh to Banlung is possible, for about US$120. It's a 5-6 hour drive to the junction near Stung Treng, then 2 hours to Banlung, plus meal breaks. Some taxi drivers in Phnom Penh specialize in this trip. Your hotel/guesthouse will probably be able to help you out.
You can book a Private Taxi online in advance for a few dollars more.
A popular way to travel to Banlung used to involve taking a ferry first to Stung Treng (or Kratie). As of June 2009 these ferries were not running.
Bus Ticket Online is available and you can check below: