The deformation behaviour of (a + B)-Ti with a very sharp texture is influenced by temperature, strain rate and the sense of stress. In this paper the plastic deformation of (a + P)-Ti is investigated in a temperature range between 295 and 1073 K in compression and tension along different directions of the sheet plane (O', 45" and 90" from the rolling direction (RD)). For this temperature range, two phenomena are observed: a dynamic strain ageing (DSA) and a asymmetry of the yield stress associated with the movement of (c + a) dislocations. Electron microscopy of specimens strained in uniaxial tension or compression along [OOOl] at 570 K shows (c+ a) dislocations moving on {liOl} and (1122) planes and an anomalous activity of (c + a) dislocations is observed on the whole range of orientation. We discuss the effect of interstitial solutes on the activity of the (c + a) dislocations between 500 and 750 K and the effect of the non-centrosymmetry for the {liOl} planes on the directional asymmetry of the yield stress associated with the (c + a) movement. Q