International cooperation is essential for the sustainable development of polar science. Spain’s strategy is to facilitate the access of the Spanish scientific community to the infrastructures of other countries, both in Antarctica and in the Arctic, to expand access to geographical areas far from our scientific infrastructures, and to diversify the possibilities of Spanish research in polar areas. The interaction with other countries allows the sharing of logistical efforts so that scientific synergies are obtained. Some of the instruments available for this purpose are the signing of memorandums of understanding (MoU) and cooperation agreements.