The Portuguese Asylum Law foresees limits to the detention of asylum seekers, in the same terms provided by the Reception Conditions Directive, in practice asylum requests presented at external borders imply systematic detention. Even with the changes in the practices that were implemented at the Lisbon Airport since March 2020, the Portuguese Asylum Law was not amended, which justifies the detention of asylum seekers both in Porto and Algarve, for instance. In this line, this analysis focus on the systematic use of detention of migrants in Portugal, arguing that the use of detention, particularly in the case of forced mobility, could constitute an obstacle to the achievement of the Sustainable Development Goal 16 (SDG 16), which aims at promoting the rule of law, nationally and internationally, and ensuring equal access to justice for all.