The studies indicate that in England and Wales, 37 percent of all women killed were murdered by their current or former partner or lover. The number of all men murdered by their current or former partner or lover was 6 percent. For every 100 men who kill their wives, 23 women kill their husbands in the United Kingdom, compared to 31 in Canada and 75 in the United States. Major risk factors were found to be previous domestic violence, a childhood victim of family violence, cohabiting, a large age disparity between the partners, drug and alcohol abuse, sexual jealousy, the threat of separation, stalking, and personality disorder. The use of a sharp implement was the most common method of killing an intimate partner in England and Wales; whereas, guns were most often used in the United States. Strangulation was another frequent cause of death for female homicide victims in England and Wales, but not in the United States. Homicides followed by suicides happened most often in the cases that involved spouse killings. The studies found that men who killed their spouses did not qualitatively differ on some risk factors from those who used nonlethal violence. A risk assessment instrument that can predict those men or women who are likely to kill their intimate partner is not yet available. Implications are drawn for practice, policy, and research. 2 tables and 56 references