Abstract :
We present the proof of the cosmic no-hair theorem for anisotropic Bianchi models in the Brans-Dicke theory. We have found that the Universe is isotropized before the extended inflation phase occurs with no strong constrains on ω, the parameter of the theory. Besides, it is shown that if any initial anisotropy is grown, inclusive more than in the general relativity case, but the Universe today would still be very isotropic.