Parricide cases in non-U.S. countries were significantly more likely than U.S. parricide cases to involve sons killing their parents alone or to have had sons identified as the primary offender. U.S. parricide cases, on the other hand, had significantly more daughters identified as the primary offender. U.S. parricide perpetrators were more likely than non-U.S. offenders to use firearms and multiple weapons; parricide offenders in other countries were more likely to use knives, blunt objects, and other weapons. Of the relatively limited number of newspaper accounts that included dispositional and release information, significantly more parricide offenders in non-U.S. countries were likely to receive lengthy prison terms compared to U.S. parricide offenders. Abuse of the child was more likely among U.S. parricide cases than in non-U.S. cases. Parricide cases in other countries were more likely to be linked with fights and alcohol and/or drug use at the time of the killing. Approximately two-thirds of the cases fit into one of Heide's three types of parricide offenders: dangerously antisocial (33 percent), severely abused (20 percent), and severely mentally ill (13 percent). The study involved a search of numerous large databases of local, regional, national, and international publications written in English and published in 2003. The analysis was based on the coding of information from 226 incidents of 1 or more children killing (n=222) or attempting to kill (n=4) 1 or more of their parents; 68 percent occurred in the United States. 1 table, 75 references, and appended data on the 73 variables coded in 226 incidents