This research investigated the scope and contents of readers' advisory services in American public libraries. Specifically, it explored librarians' perspective on the following issues: definition, function, and training objectives of readers' advisory services; the problems and challenges librarians face; their opinions on future developments in readers' advisory services. The data collection was carried out by an online questionnaire and the participants included 106 librarians who provided readers' advisory services in American public libraries. Through literature reviews and research results, the author provides suggestions for readers' advisory services in Taiwan's public libraries to consider. The author also provides suggestions for American public libraries that participated in this research, Taiwan's public libraries that intend to provide readers' advisory services in the future, and Library and Information Science related majors in the educational realm.