The paper focuses on developing constitutive models for superplastic deformation behaviour of near-α titanium alloy (Ti-2.5 Al-1.8 Mn) at elevated temperatures in a range from 840 to 890 C and in a strain rate range from 2× 10− 4 to 8× 10− 4 s− 1. Stress–strain experimental tensile tests data were used to develop the mathematical models. Both, hyperbolic sine Arrhenius-type constitutive model and artificial neural-network model were constructed. A comparative study on the competence of the developed models to predict the superplastic deformation behaviour of this alloy was made. The fitting results suggest that the artificial neural-network model has higher accuracy and is more efficient in fitting the superplastic deformation flow behaviour of near-α Titanium alloy (Ti-2.5 Al-1.8 Mn) at superplastic forming than the Arrhenius-type constitutive model. However, the tested