Data indicate there are over three times as many male victims of murder and nonnegligent manslaughter as female victims. Further, over six times as many males as females are arrested for murder and nonnegligent manslaughter, and the victimization and arrest rates for males are increasing faster than those for females. The distribution of victimization and arrest rates across age groups is much 'flatter' for females than for males. Also, race is a better predictor of victimization and arrest rates than sex (nonwhite females have higher rates than white males). Homicides by and against females are primarily intersexual (females are more likely to kill and be killed by males); such homicides are also predominantly intraracial. Generally, female offenders are perceived as being more disturbed than male offenders. There are a number of areas in which so little information is currently available that no conclusions can be drawn; e.g., little is known about differences between the sexes in the areas of weapon use, prior record, alcohol use, and location of the assault. There is little persuasive evidence for biological theories to explain female violence, and there has not been much of an effort to set forth both individual and sociological data, and attempts to devise theory to explain those data are almost nonexistent. Future research should (1) aim at determining the patterns of homicide events involving female victims or offenders, (2) compare data between jurisdictions both in this country and abroad, and (3) ground theory development and testing in both individual case data and sociological data. Tabular data and 58 notes are provided.