Summary During the two-day symposium, participants exchanged information on the situation of LGBT persons deprived of their liberty, a particularly ‘invisible’ minority group subjected to discrimination in detention. Due to the strong taboo around sexual orientation and gender identity issues, LGBT persons face many situations of risk from the moment they are deprived of their liberty until their release. Although discussions have mainly focused on the risks faced by LGBT persons during their arrest or detention by the police and in prison, it was stressed that all types of deprivation of liberty expose this particularly vulnerable population to abuse of all kinds. In the prison context in particular, LGBT persons are typically consigned to the bottom of the informal hierarchy and often find themselves at the mercy of other detainees. They are victims of acts of violence and often do not enjoy the same detention conditions as other detainees, while prison authorities tend to ignore (or even encourage) discrimination against them. The situation of transgender persons was the subject of specific discussions as this population faces particular problems and needs, notably with regard to their allocation within detention centers and their access to health care. The separation of LGBT persons from the rest of the incarcerated population is sometimes considered by the detaining authorities as the only effective way of protecting them from violence and abuse. However, this type of measure is controversial and regarded as stigmatising, even discriminatory, and one that should only be applied as a last resort and with the consent of the person concerned. The use of prolonged solitary confinement - even as a means of protection - was denounced as a possible form of torture and could therefore run counter to the "do no harm" principle under which NPMs are committed never to take any action that is prejudicial to detainees. In order to carry out their preventive mandate effectively, it is important that NPMs prepare their visits to places of detention. While 5