Introduction: Little is known about the risk and protective factors for youth sexual violence (SV) perpetration across different types of relationships. This study examined factors associated with perpetrating SV against a dating partner and a same-sex peer.Methods: Analyses were based on data from a survey conducted in 2004 with public school boys and girls in grades 7, 9, 11, and 12 (N=4,131) in a high-risk, urban school district in the United States. SV perpetration was defined broadly to include forcing someone, about the same age and of the same or opposite sex as the respondent, to have sex or to do something sexual that they did not want to do. Analyses examined the associations between risk and protective factors and SV perpetration, adjusting for SV victimization and demographic characteristics.Results: Findings revealed that 2.1% of respondents reported perpetration against a same-sex peer and 3.2% reported perpetration against a date during the past 12 months. Victims of SV for each relationship type were more likely than non-victims to perpetrate SV. A combination of factors across the individual, relationship, and community level were significantly associated with SV perpetration and there were both shared and unique factors across the relationship types.Conclusion: Data suggest that programs to prevent SV perpetration for both relationship types should start when students are young, with particular focus on middle school boys. Prevention efforts should have slightly different foci to address these 2 types of SV perpetration. [West J Emerg Med. 2013;14(4):329–340.]