In recent years, a lot of work has been done for supporting the operational management of container handling operations in seaports. However, the train-to-train container transshipment problem, in which containers have to be interchanged between trains, has been largely ignored. Containers are handled by rail mounted cranes. The time needed for completing the transshipments using multiple cranes is to be minimised. The contribution of this paper is to put forward a metaheuristic approach to deal with this challenging problem that has not been tackled before. The problem is first decomposed into three subproblems: (1) the assignment of a destination to each train, (2) the determination of container positions on the train wagons and (3) the determination of the operations sequence for the different cranes that perform the actual transshipments. The first subproblem is solved in a heuristic manner while the second subproblem is solved to optimality. The third subproblem is tackled by a Variable NeighbourhoodDescentmetaheuristic procedure. This approach is validated on a set of generated test problems. Solutions are obtained in a reasonable amount of calculation time.