Optimizing pediatric antimicrobial stewardship is challenging. In this retrospective study, we evaluated 515 original e-mails to 482 members of the Sharing Antimicrobial Reports for Pediatric Stewardship (SHARPS) Collaborative electronic mailing list (idlistserv@kids.wustl.edu). The plurality of threads discussed clinical practice guidelines, and pharmacists were most likely to initiate and respond. Representation was geographically diverse within and outside the United States.