The purpose of this study was to evaluate the effectiveness of a public/community health online preceptor education program on knowledge of the preceptor role and self-efficacy to perform in the preceptor role. Forty-eight public/community health nurses from five states completed an online education program, a 32-item quiz and a preceptor self-efficacy instrument. Preceptor self-efficacy and knowledge scores improved significantly after completing the online education program compared to pretest scores. Previous experience as a preceptor, age, and place of employment, were not correlated with preceptor self-efficacy scores. Previous preceptor education and highest level of education completed were positively correlated with preceptor self-efficacy scores. Previous preceptor education was reported by 39.6% of nurses. However, there was no standard curriculum for these education programs. The results of this study support the use of online education as a method for enhancing preceptor knowledge and confidence in the preceptor role.