ENMigration and security as social phenomena, which in recent times have often been levelled or even staged against each other. Migration can sometimes pose certain challenges to the interests of the state if it is perceived as a threat to national security. This perception can lead to the implementation of various political or legal measures and instruments aimed at protecting borders, regulating immigration flows and monitoring the movement of migrants. The European Parliament has tried to tighten border controls and improve the ability of Member States to manage the flow of people arriving in Europe. To achieve this, the new Pact on Migration and Asylum was approved, which proposes to better address the complexity and challenges of migration management, while ensuring that the rights and needs of illegal migrants are respected and protected. Over the past few years, the countries of the European Union have from time to time reintroduced border controls within the Schengen area, which often last for a long time. In order to preserve free movement while addressing real security threats, the European Commission presented its proposal for a revision of the Schengen rules in 2021. In February 2024, Parliament reached a provisional agreement with national governments on rules stressing that the reintroduction of border controls is a last resort. EU countries can exceptionally reintroduce border controls when there is a serious threat to public policy or internal security. This article analyses the challenges posed by migration processes to contemporary public security, focusing on the case of Lithuania. The article analyses the impact of irregular migration on the public security aspects of Lithuania and discusses possible solutions to address these challenges.The article reviews the migration situation in Lithuania over the last decade using statistical data and assesses the decision-making challenges for the actors involved in migration processes, as well as providing an overview of the latest regional legal framework. Keywords: irregular migration, migration processes, public security. [From the publication]