Criminal sanctions, in spite of their obvious limitations, play an important role in the prevention of juvenile crime. In spite of international admonitions against the use of detention, Vietnam like many other South-East Asian countries still relies heavily on the deprivation of liberty, in both specialized juvenile institutions and adult prisons, in handling juvenile offenders. Because imprisonment, according to international standards, is meant to be used only as a last resort and for the shortest period of time possible, juvenile justice research has tended to ignore what is going on in places of detention and focus instead on diversion and alternatives to detention. This article focuses on Vietnamese law concerning the prison regimes applicable to juvenile detainees and the extent to which it complies with internationally accepted standards and norms. It reviews existing measures for the protection of juveniles against all forms of violence during their incarceration, including abusive disciplinary measures and the absence of independent oversight of prisons. It also considers arguments for and against the building of juvenile prisons to separate juveniles from adults as required by article 37 of the Convention on the Rights of the Child. It concludes with recommendations for legal reforms.