In this chapter we introduce the concepts of KT-pseudo
-univex-II, and FJ-pseudo
-univex-II functions. The main objective of introducing these functions is to establish characterizations for efficient solutions to nondifferentiable multiobjective programming problems. Moreover, characterizations for efficient solutions by Fritz—John optimality conditions are also obtained. Furthermore, the Mond—Weir type dual problem is studied and weak, strong, and converse duality results are established involving the aforementioned class of functions.