Constantine's Mohamed Boudiaf International Airport has a few international flights to France and numerous daily flights to Algiers.
The bus station is a couple of kilometres south of the town centre and Casbah. Buses leave roughly every hour for Algiers (DA760, six hours), Annaba (DA280, four hours), Batna (DA220, three hours) and Setif (DA200, three hours). A taxi from the city centre to the bus station costs DA200.
Constantine's train station is a slightly scary walk across a wobbly bridge from the Casbah. There's a nightly train to Annaba but it leaves at the uncivilised time of 2.50am (from DA245, 2½ hours). A daily train heads to Algiers (from DA985, 6½ hours) at 6.40am and twice daily trains serve Batna (DA250, 1½ hours) and Setif (from DA335, 2½ hours).