In this paper, we establish some results regarding the optimality conditions and duality properties for properly efficient solutions of a constrained bilevel multiobjective fractional programming problem (P) with an extremal-value function. These results are obtained by applying a parametric approach to reduce the problem (P) to a parametric problem (P^μ) with μ ∈ R^p, and we obtain optimality conditions for properly efficient solutions for these problems. Furthermore, we define a dual problem of (P^μ) and we establish some results on duality.