The growing interest in mobile ad hoc networks (MANETs) is reflected in the noticeable publication and standardization effort during the past decade. The new standards always include a certain routing protocol but accept the use of other possibilities as well; the reason is that there is no single routing protocol that perfectly adapts to any scenario. This chapter provides new approach to MANET routing in detail, describing available multicriteria optimization techniques and summarizing recent proposals of applying mathematical methods to MANETs. It analyzes the mathematical characteristics of a multicriteria optimization problem, as a first step to the analysis of the existing multicriteria optimization methods for decision making and its subsequent application to MANET routing. MANET routing is a key aspect in the development and eventual success of mobile ad hoc networking.