Due to the Lithuanian “push-back” policy, the number of persons irregularly crossing the LithuanianBelarusian border is decreasing. However, irregular migration remains significant in Lithuania. Migrants who irregularly cross the EU border in Latvia use Lithuania as a transit country to reach other EU countries. Such migrants in secondary migration found in Lithuania can be returned to Latvia following the readmission agreement and/or Dublin III Regulation. The paper aims to identify whether Lithuanian law and practice regarding irregular migrants in secondary migration from Latvia comply with international and EU law requirements. To achieve this aim, the paper defines the meaning of secondary migration of irregular migrants from Latvia, determines the International, EU and Lithuanian law and provisions of the Readmission agreement with Latvia applicable to secondary migration, and presents a practice of Lithuanian authorities in organising and performing the return to Latvia of migrants in secondary migration.