Men's violence against women is analysed in the context of heterosexual relationships which have ended. The process of separation and the negotiations on custody, visitation and maintenance are affected by men's use of violence and these processes also change the conditions for and the extent of that violence. Violence can be a reason for women to take the initiative in relation to separation and, at the same time, men can use violenee or threats of violence to negate women's initiative in seeking separation. Put differently, women's rights to end heterosexual relationships are violated by men's use of violence. The pur pose of the present study is to describe how, and to some extent explain why, men's use of violence against women varies over time in a relationship. Such knowledge can be applied in at least two areas: first, risk assessment by and for women who considel' starting a separation process; second, enhancing the way professionals work with negotiations between parents after separation. "Violence" is understood as an umbrella-concept covering a number of forms of violence, which in tum includes a number of different violent or violating acts. Different forms of violence vary different ly over time in a relationship. A survey of women with experience of separation, but not necessarily of violence, was used to gather information on men's violence from the first period of cohabitation to the period after separation and negotiations on custody. Before the process of separation was initiated, men 's use of violence often escalated. All forms of violence were relatively common during the 6 months prior to the decision to initiate separation. During and after separation, sexual and physical violence decreased or stopped completely for most women, while threats, wamings and psychological violence continued at about the same level as before. Very few men started using physical violence during or af ter the separation. Negotiations on custody, visitations or maintenance are affected by a father's lise of violence, in particular psychological violence, through a mother's fears. Professionals should improve the methods used if negotiations are to become fair in the sense of violence not giving advantages to fathers.