Homicide-suicides (HS), the murder of one or several individuals followed by the perpetrator's suicide, are a major public health problem. Despite an abundant literature on predictors of this complex phenomenon, findings have been contradictory. Our aim in this systematic review was to examine the characteristics of HS perpetrators and more globally the risk factors associated with HS. We searched six electronic databases from inception to October 1993 to August 2019 and identified 49 eligible studies. We extracted eight categories of risk factors, structured as follows: sociodemographic characteristics; relationship dynamics and family situation; victimological factors; psychopathological vulnerabilities; legal history; life experiences; motivational factors; and modus operandi. Perpetrators of homicide-suicides were older and more likely to be male, older than homicide or suicide perpetrators. Studies also reveal an early history of adversity during childhood, legal issues in the past, as well as the exposure to stressful and/or traumatic events shortly before the criminal act as risk factors. Most of HS are perpetrated in an intra-familial setting and occur in the context of recent separation, divorce, and domestic conflicts. Finally, the present review shows the significant contribution of psychopathological factors (e.g., depressive disorder, psychotic delusional convictions) in the HS phenomenon.Read less <