This work demonstrates and explains how, during the hot deformation of a Zr alloy in the two-phase field, the texture developed in the α phase is influenced by that developed in the β phase. For this Zr-2.5wt.%Nb alloy was hot compressed in the α+β phase field (700, 750 and 800 °C) at 0.1 s-1 to a true strain of 1.1. The microstructure and texture were characterized using scanning electron microscopy and electron backscatter diffraction. The flow curves showed a sharp drop in flow stress at ε≈0.01 due to plastic deformation induced α to β phase transformation. At 700 °C, α-Zr developed parallel to compression axis (||CA) (as is commonly observed in α-Zr system), whereas at 750 and 800 °C ||CA formed. At all studied temperatures, β-Zr developed {001} and {111} texture components that were shown to be dependent on the elongated morphology of the α-Zr grains and not on the α-Zr texture. From experimental observations and thermodynamic calculations of the free energy changes in absence and presence of stress, it was shown that the formation of ||CA in α-Zr occurred by migration of β-Zr into of α-Zr followed by the reverse β to α transformation (through Burgers orientation relationship) driven by low flow stress in of α-Zr and low Nb content in the transforming β-Zr. It was concluded that the presence of β-Zr with ||CA and ||CA is a necessary condition for the formation of ||CA in α-Zr. In addition, temperature promotes the development of in α-Zr through enhanced boundary mobility of β-Zr into harder α-Zr.