Background: Aggressive behavior is a severe symptom of diseases with varying etiologies. Deep brain stimulation (DBS) in the posteromedial nucleus of the hypothalamus (pHyp) is an alternative therapy for extreme cases and shows promising results. This study investigated the safety and clinical effect of pHyp DBS for aggressive behavior. Methods: We conducted a systematic review (PROSPERO registration ID: CRD42018100871) following PRISMA guidelines; extracting data from original English studies published between 1973 and 2019 from the PubMed, Embase, Scopus, and LILACS databases, using the search terms “deep brain stimulation”, “posteromedial hypothalamus”, "aggression", and “aggressiveness”. The main outcome we analyzed was aggressive behavior measured on the Overt Aggression Scale (OAS) or the Inventory for Client and Agency Planning (ICAP) before and after DBS. The secondary outcome was the incidence of adverse effects. Findings: Four studies published between 2008-2015 met the eligibility criteria; three clinical series and one case report (N:19 patients). The mean clinical improvement of patients evaluated with OAS and ICAP was 67.5% and 71.8% respectively. The incidence of adverse effects was 36.8%, with only one major complication. Interpretation: The four studies available have low statistical power. Based on the GRADE methodology, the results indicated a weak recommendation in favor of the use of pHyp DBS for aggressive behavior. Our analysis found pHyp DBS to be a safe alternative treatment for intractable aggressiveness. The pattern of stimulation is an important factor and better results have been shown using low frequency and amplitude in order to avoid potentially severe side effects.Funding Statement: None.Declaration of Interests: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.