This study analyzes the impact of transnational migration activism on the San Diego–Tijuana region, as well as the impact of migration policies. The need for communication and information sharing between non-governmental organizations (NGOs) located in San Diego and Tijuana has led to the creation of transnational social networks. These NGOs have received financial and training support from international organizations or Christian churches, and their transnational activities vary according to their individual circumstances, which determines the challenges they face in supporting migrants. The NGOs have been able to develop support activities and transnational activism to assist migrants seeking to reach the US with social services, advocacy, and human rights defense, as well as providing legal services to deported migrants and refugees. The most significant challenges mentioned by the NGOs include the entry restrictions imposed by US immigration authorities and the lack of sufficient financial resources.