Clinical cases of frontal lobe lesions have been significantly associated with acquired aggressive behaviour. Restoring neuronal and cognitive faculties of aggressive individuals through invasive brain intervention raises ethical questions in general. However, more questions have to be addressed in cases where individuals refuse surgical treatment. The ethical desirability and permissibility of using intrusive surgical brain interventions for involuntary or voluntary treatment of acquired aggressiveness is highly questionable. This article engages with the description of acquired aggressiveness in general, and presents a (...) rare clinical case to illustrate the difficulties of treating this population. To expand the debate further, this article explores the ethics related to invasive brain surgery in three parts: a) it examines coercive involuntary invasive brain surgery for the benefit of protecting others on individuals suffering from acquired aggressiveness who lack decision-making capacities to consent; b) it addresses voluntary psychosurgery on individuals suffering from acquired aggressiveness who are competent to consent; and, c) it questions whether acquired aggressive individuals, who are legally competent, have a duty to consent to invasive brain surgery, in order to maintain their autonomy by reducing or even eliminate their aggressive drives. Ensuring the safety and efficacy of surgical brain interventions could increase the ethical permissibility of voluntary treatment, but it would not necessarily entail ethical justification for proceeding with invasive brain surgery for treatment of intractable acquired aggressive behaviour. (shrink)