Objective: To assess the effectiveness of an online course for public librarians on helping patrons reduce saturated fat. Design: Pre- and posttest design along with a 6-month follow-up survey. Setting: Online nutrition course. Participants: 100 (8 males, 92 females) completed the course, and 29 completed the follow-up survey. Intervention: Completion of an online course. Main Outcome Measures: Self-efficacy, expectancies, and knowledge were assessed at pre- and posttest. Self-efficacy, expectancies, and use of course content were assessed at 6-month follow-up. Analysis: Paired-samples t tests. Results: Knowledge increased significantly (P less than 0.001). Self-efficacy significantly (P less than 0.001) increased from the pre- to posttest, and this increase remained significant at the 6-month follow-up as compared to pretest (P less than 0.001). Expectancies also increased significantly from pre- to posttest (P less than 0.001) and remained high at 6 months, but they were not significantly different from baseline (P = 0.178). At 6-month follow-up, 39% of the participants had used the information from the course to find resources for a patron with a health-related question, and 82% had used the information from the course to help a friend or family member. Conclusions and Implications: This small pilot study with librarians shows that an online course can be an effective way to increase self-efficacy about helping patrons with nutrition-related questions. (Contains 3 tables and 1 figure.)