Most of the work done on superplastic forming is related to sheet metal forming. Very limited studies have been directed toward investigating the superplastic tube forming process. In this work, Finite Element (FE) simulations are carried out in order to simulate the superplastic tube forming process. The analysis is conducted for the superplastic magnesium alloy AZ31 at 400°C. The results clearly demonstrate that there is a significant difference between tube forming and sheet metal forming in terms of forming pressure profiles. In addition, the effects of tube radius, free forming length, and contact on the tube forming process are investigated.