As many as one-quarter of uroxicides [Johnson and Hotton (2003) Homicide Studies 7:58-84] and filicides [Wilczynski (1997) Child Homicide, London: Greenwich Medical Media] end in the suicide of the offender. As in homicide-or suicide-only events, homicide-suicide (HS) can arise from a variety of circumstances, ranging from relationship breakdown, to financial and health problems. However, to date our understanding of this disheartening phenomenon remains limited. As an HS event comprises both a homicidal and a suicidal component, the question of whether HS is primarily an extended suicide dominated by weariness or an alternate form of homicide overwhelmed by anger is a contentious topic. This article argues that there are at least two types of HS, with one type being dominated by hostility against the victim, whilst in the other hostility is not apparent. Based on HS events that occurred between 1989 and 2003 in Hong Kong, significant differences are found between these two types of HS in terms of offender and victim characteristics, antecedent, offender-victim relationships, situational factors and modes of killing. This is the first HS typological classification built on the hostility debate that has been validated with empirical data.