In times of increasing migration flows, Greece is often viewed as the gateway to Europe for significantly high numbers of asylum-seeking individuals, including unaccompanied minors. Between 2016 and 2020, under Greek law unaccompanied children were to be temporarily placed in a protective environment upon irregular entry, pending referral to suitable accommodation. However, in reality they were being subjected to detention procedures instead. Giving voice to migrant children and professionals throughout, the author combines legal analysis with criminology and unveils the discrepancy between the law and practice. The findings demonstrate that unaccompanied children in Greece are criminalised through detention processes, while being deprived of the right to be heard. This book promotes child-friendly practices in the international migration setting, with a view to safeguarding the fundamental rights of unaccompanied minors experiencing detention upon arrival in host countries.