In this paper phenomenological descriptions of the experiential structures of suicidality and of self-determined behaviour are given; an understanding of the possible scopes and forms of lived self-determination in suicidal mental life is offered. Two possible limits of lived self-determination are described: suicide is always experienced as minimally self-determined, because it is the last active and effective behaviour, even in blackest despair; suicide can never be experienced as fully self-determined, even if valued as the authentic thing to do, because no retrospective re-evaluation from some future vantage is possible. The phenomenological descriptions of the possible scope of lived self-determination in suicidality, presented in this paper, should prove to be extremely helpful in three different fields of interest: (a) ethical debates regarding the pros and cons of autonomous or heteronomous suicide; (b) clinical day-to-day practice with respect to treating suicidal people; (c) people who suffered a suicidal crisis, attempted suicide or lost loved ones through suicides. (155 words).