We study the gendered impact of recommendations at different stages of the hiring process. First, using a large sample of reference letters from the academic job market for economists, we document that women receive fewer `ability' and more `grindstone' letters. Next, we conduct two experiments --- with academic economists and a broader, college-educated, population ---analyzing both recommendation and recruitment stages. These confirm that recommendations are gendered and impact recruitment. We elicit gender views and beliefs about the effectiveness of different letter types, uncovering that gender attitudes and strategic behavior based on erroneous beliefs explain referees’ choices. Finally, we decompose gender recruitment gaps into two components: one capturing differences in treatment of candidates with identical qualities, the other reflecting recruiters’ failure to account for gendered patterns in recommendations. We show that recruiters' failure to recognize the gendered nature of reference letters undermines visible efforts to improve diversity in hiring.