Trade was an important source of income. The growing difficulties between the Romans and the Parthians hindered the profitable trade between east and west. The only independent state between both super powers, Kommagene, was an acceptable trading partner for the Romans as well as the Parthians. The Kommagenian traders could travel freely through the land of the Parthians. They brought among other things, exotic animals and spices from India and silk from China.

Antiochos could levy heavy tolls, as he controlled the passes of the Taurus Range as well as the crossings of the Euphrates river. Because of its wealth, Kommagene was not only a transit point but could afford to import costly goods as well.

The traders sold their valuable wares in Samosata to Roman traders and prosperous Kommagenian citizens. Under the reign of Antiochos, Samaosata became the centre of trade between the east and west. Here, Parthians, Kommagenians, Romans, Greeks and Arabs met.