Abstract This study aims to determine the different deformation mechanisms of grade 702 zirconium under uniaxial tension and at room temperature. The grade 702 zirconium tested had undergone an α → β → α cycle at a slow cooling rate (∼ 15° s −1). Three deformation mechanisms were identified: prismatic slip, (1012) 〈101〉 twinning and (1121) 〈1126〉 twinning. The critical resolved shear stress for prismatic slip, (1012) 〈1011〉 twinning and (1121) 〈1126〉 twinning was also determined. The effect of the non-uniform redistribution of the hardening elements on location through the grain of the various mechanisms and on the tendency for localized deformation to develop is also discussed.