This chapter explores the optimization approach known as multivariate inverse artificial neural network (ANNim). This computational framework couples a metaheuristic algorithm with a feed-forward neural network to determine the optimal independent variables for a desired amount. The main objective of this approach is to reverse the direction of an artificial neural network by converting it into a multivariate objective function, which has brought great interest in its implementation for solving several problems in energy systems. The chapter is divided into four sections. Section 1 presents the introduction to inverse artificial neural networks. Section 2 presents the mathematical development for its integration in solving problems in the engineering area. Section 3 shows how various studies have successfully integrated it into solving problems in the energy sector. Section 4 exemplifies its implementation through an experimental case study.