Victims of sexual assault are often advised to seek postassault medical care to have a forensic exam, which includes evidence collection (termed a "sexual assault kit" [SAK]). After the exam, law enforcement personnel are supposed to submit the SAK to a crime laboratory for analysis. However, recent media reports suggest that in many communities throughout the United States, thousands of SAKs are left untested. Few studies have examined the rate at which law enforcement submits SAKs to crime labs or the factors that may predict them to do so. Thus, the purpose of this exploratory study is twofold: (a) to examine the percentage of SAKs law enforcement submits to crime labs in cases in which a sexual assault nurse examiner (SANE) performed the exam with adult victims and (b) to explore whether assault and law enforcement characteristics predict whether SAKs are submitted to a crime lab. This study found that only 58.6% of the SAKs were submitted to the crime lab within a large Midwestern county. Using binary logistic regression, this study found that kits were significantly as likely to be submitted when there were documented physical (nonanogenital) injuries compared with kits that did not have documented physical injuries. In addition, kits that were handled by a law enforcement agency that had a high level of engagement with the SANE program were significantly as likely to be submitted as law enforcement agencies with a low or medium level of engagement. Kits were significantly less likely to be submitted when victims cleaned themselves after the sexual assault (e.g., bathing). No association was found between kit submission and the victim-offender relationship, suspected drug-facilitated sexual assault, anogenital injury, and when the victim consumed alcohol or drugs before the assault. This article concludes with a discussion of the implications for research and practice. (Contains 2 tables.)