2005-Oujda International Conference on Nonlinear Analysis, Oujda, Morocco. Electronic Journal of Differential Equations, Conference 14 (2006), pp. 135-147. Title: Optimal controls for a class of nonlinear evolution systems Authors: Abdelhaq Benbrik (Univ. Mohammed 1er, Oujda, Maroc) Mohammed Berrajaa (Univ. Mohammed 1er, Oujda, Maroc) Samir Lahrech (Univ. Mohammed 1er, Oujda, Maroc) Abstract: We consider the abstract nonlinear evolution equation $\dot{z}+ Az =uBz +f$. Viewing $u$ as control, we seek to minimize $J(u)=\int_{0}^{T}L(z(t),u(t))\,dt$. Under suitable hypotheses, it is shown that there exists an optimal control $\overline{u}$ and that it satisfies the appropriate optimality system. An example involving the $p$-Laplacian operator demonstrates the applicability of our results. Published September 20, 2006. Math Subject Classifications: 49J20, 49K20. Key Words: Optimal control; monotone operator; compact embedding; $p$-Laplacian; bilinear system.