The book Immigrants in Detention - International and Polish Perspective (the second volume of a three-volume series dedicated to detention) focuses on European standards (the Council of Europe and the EU) regulating detention ordered in procedures considering the return of illegally residing immigrants and providing international protection. These laws are confronted with the UN documents, mainly the International Covenant on Civil and Political Rights as well as the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment. Theoretical speculations are illustrated with Polish, Hungarian, Belgian, and (to a limited extent) American practices and decisions issued by UN treaty bodies, as well as tribunals in Strasbourg and Luxembourg.