This study aimed to develop internet health information education program, and to explore the program's feasibility and preliminary effects. We made use of an intervention mapping approach and adopted as conceptual framework the information-motivation-behavioral skills model to develop the program. We evaluated the feasibility and the impact of the education program using a single-group pretest-posttest design using generalized equation estimation. Eleven older adults participated in the classes from January 25 to February 22, 2019. Each outcome of the behavioral theory-based components of the program-computer/Web knowledge (p < .001), attitude toward internet-based health information (p = .002), eHealth literacy score (p < .001), searching performance scores (p < .001), and level of understanding of internet-based health information (p = .002)-showed significant improvement immediately after the intervention. This pilot study reveals that a behavior theory-based education program for utilizing internet-based health information is an effective way to increase older adults' eHealth literacy.