Data for this study are part of a larger database of all domestic incident reports filed in 1978 by 28 police departments of a midwestern county. All reports in which violence by family members and cohabitating or dating persons was identified were included in this study sample. The analysis focused on victim and offender characteristics, the offenses committed, offense location, and other incident characteristics. Violent incidents among couples (married, unmarried, or divorced) constituted the majority (58 percent) of incidents labeled 'domestic' by police. For couples involved in ongoing relationships, the intensity of the involvement was expressed in a corresponding intensity of violence. Among these couples, the assaults tended to be more physical than verbal in comparison to assaults by ex-spouses. Differences between the violent incidents of married compared to dating couples were related to incident location and to sociocultural and racial patterns of marriage. Because of the growing trend toward postponing formal marriage in favor of prolonged, informal intimate relationships, police should respond to this violence in the same manner they respond to marital violence, i.e., with arrest, 17 tables.