Tan Son Nhat International Airport (HCMC) Taxis to central districts (around 190,000d) take about 30 minutes. There's also an air-conditioned Route 152 bus (6000d, every 15 minutes, 6am to 6pm, around 40 minutes).
Noi Bai Airport (Hanoi) Taxis to the centre cost 400,000d and take around 50 minutes. Jetstar shuttles (35,000d) and Vietnam Airlines minibuses (50,000d) run hourly. The Route 17 public bus to Long Bien bus station is 5000d.