Objective: Sexual Assault Response Teams (SARTs) seek to improve the response to sexual assault by coordinating the efforts of police, prosecutors, nurses/doctors, victim advocates, and other sexual assault responders. However, SARTs vary with respect to their structure, that is, the composition and organization of their team. Therefore, the current study explored the relationship between SART structure and effectiveness. Method: A random sample of N = 172 SART leaders was interviewed. Participants reported on SART structural characteristics and their perceptions of their team’s effectiveness at improving victims’ help-seeking experiences, victims’ participation in the criminal justice system, police processing of cases, and prosecution of cases. Results: Cluster analysis revealed 3 types of SARTs: “Low Adopters” utilized fewer formal structures and were less likely to institutionalize collaborative processes into their teamwork; “High Adopters” utilized more formal structures and were more likely to institutionalize collaborative processes, but did not engage in program evaluation as a multidisciplinary team; and “High Adopters Plus Evaluation” were similar but also engaged in evaluation as a team. High Adopters Plus Evaluation were perceived as significantly more effective than Low Adopters across all domains. High Adopters Plus Evaluation were perceived as more effective at improving victims’ participation in the criminal justice system than High Adopters. SARTs with broader active membership from more stakeholder groups also tended to have higher perceived legal effectiveness. Conclusions: SARTs should consider broad-based active membership and adopting formal structures and collaborative processes to organize their team. Future research can continue to examine factors that contribute to SART success. (PsycINFO Database Record (c) 2016 APA, all rights reserved)