Objective: This prospective, longitudinal study explored the impact of a continuing education class on librarians’ knowledge levels about and professional involvement with systematic reviews. Barriers to systematic review participation and the presence of formal systematic review services in libraries were also measured.Methods: Participants completed web-based surveys at three points in time: pre-class, post-class, and six-months’ follow-up. Descriptive statistics were calculated for demographics and survey questions. Linear mixed effects models assessed knowledge score changes over time.Results: Of 160 class attendees, 140 (88%) completed the pre-class survey. Of those 140, 123 (88%) completed the post-class survey, and 103 (74%) completed the follow-up survey. There was a significant increase (p<0.00001) from pre-class to post-class in knowledge test scores, and this increase was maintained at follow-up. At post-class, 69% or more of participants intended to promote peer review of searches, seek peer review of their searches, search for grey literature, read or follow published guidelines on conduct and documentation of systematic reviews, and ask for authorship on a systematic review. Among librarians who completed a systematic review between post-class and follow-up, 73% consulted published guidelines, 52% searched grey literature, 48% sought peer review, 57% asked for authorship, and 70% received authorship.Conclusions: Attendance at this continuing education class was associated with positive changes in knowledge about systematic reviews and in librarians’ systematic review–related professional practices. This suggests that in-depth professional development classes can help librarians develop skills that are needed to meet library patrons’ changing service needs.