The objective of this study is to examine continuity of intimate partner aggression (IPA), which is defined as repeated annual involvement in IPA, across respondents' life course and into the next generation, where it may emerge among adult children. A national, longitudinal, and multigenerational sample of 1,401 individuals and their adult children is analyzed. Annual data on IPA severity and physical injury were collected by the National Youth Survey Family Study across a 20-year period from 1984 to 2004. Three hypotheses and biological sex differences are tested and effect sizes are estimated. First, findings reveal evidence for life course continuity (IPA is a strong predictor of subsequent IPA), but the overall trend decreases over time. Second, intergenerational continuity is documented (parents' IPA predicts adult children's IPA), but the effect is stronger for female than for male adult children. Third, results from combined and separate, more restrictive, measures of victimization and perpetration are nearly identical except in the intergenerational analyses. Fourth, evidence for continuity is not found when assessing physical injury alone. Together, these findings imply that some but not all forms of IPA are common, continuous, and intergenerational. Life course continuity appears stronger than intergenerational continuity.