Policy makers and researchers give psychological abuse considerably less attention than physical abuse in the partner abuse area. One reason for the relative neglect of psychological abuse is that there are difficulties in arriving at a common definition of psychological abuse that might be useful to both the mental health and legal professions. Another reason for the relative neglect of psychological abuse has been an implicit assumption that physical abuse exacts a greater psychological toll on victims than does psychological abuse. At the extreme level of physical abuse, this assumption seems defensible, but at levels of physical aggression that are most common in marriage and long-term relationships, psychological abuse appears to have as great an impact as physical abuse. Even direct ratings of psychological and physical abuse by women in physically abusive relationships indicate that psychological abuse has a greater adverse effect on them than physical abuse. Retrospective reports, longitudinal research, and treatment dropout research all provide evidence that psychological abuse can exact a negative effect on relationships that is as great as that of physical abuse. Finally, psychological abuse almost always precedes physical abuse, so that prevention and treatment efforts clearly need to address psychological abuse. Eight measures of various forms of psychological abuse that have reasonable psychometric properties and considerable construct validity are reviewed and a definition of psychological abuse in intimate relations is provided.