More than 70% of the oil production in Brazil employs gas-lift as the artificial lift method. An effort is being done by some operators to complete new gas-lift wells with downhole pressure gages. This paper proposes a Non-Linear MPC algorithm to control a group of wells receiving gas from a common Gas-Lift Manifold. The objective is to maximize an economic objective while minimizing the oscillations of the pressures at the manifold and at the bottom of the wells.