International cooperation is essential for the sustainable development of polar science. Spain's strategy is to facilitate the Spanish scientific community's access to the infrastructures of other countries, both in the Antarctic and the Arctic, to increase access to geographical areas that are remote from our scientific infrastructures, and to diversify the possibilities of Spanish research in the polar regions. Interaction with other countries makes it possible to share logistical efforts in a way that leads to scientific synergies. Some instruments available for this purpose included the signing of memoranda of understanding (MoUs) and cooperation agreements.