This article presents results from a meta-analytic review designed to summarize data on intimate partner violence (IPV) risk factors gained between the years 1980 to 2000, and to identify areas that need additional empirical work. Dutton’s (1995a) nested ecological theory guided the choice of risk factors examined in this study. Dutton’s system has four levels of factors relating to individual offenders and their environment: the macrosystem level -- includes cultural values and beliefs; the exosystem level -- includes the offender’s formal and informal social structures; the microsystem level – characteristics of the immediate setting in which the abuse took place; and the ontogenic level – specific to the abuser’s developmental history. For this study, the exosystem, microsystem, and ontogenic levels were examined for both offenders and victims of IPV. A literature search was conducted to identify studies for possible inclusion in the review. Based on a set of established criteria, 85 studies were examined to identify risk factors most strongly related to intimate partner abuse perpetration and victimization. A review of the studies produced 308 distinct effect sizes which were then used to calculate composite effect sizes for 16 perpetration and 9 victimization risk factors. The review found that large effect sizes existed between perpetration of physical abuse and five risk factors (emotional abuse, forced sex, illicit drug use, attitudes condoning marital violence, and marital satisfaction). Moderate effect sizes were observed between perpetration of physical abuse and six risk factors (traditional sex-role ideology, anger/hostility, history of partner abuse, alcohol use, depression, and career/life stress). Finally, a large effect size was found between physical violence victimization and the victim using violence toward her partner, while moderate effect sizes were calculated between female physical violence victimization and depression and fear of future abuse. Study limitations and suggestions for future research are discussed. References and 4 tables