In an intensive care unit (ICU), patients' families play a very important role; however, they often lack medical knowledge and are extremely anxious, which could affect their ability to take care of the patients. The effects of giving conventional paper‐based instruction are limited in terms of improving patients' families' understanding of the facilities and the rules in the ICU and in reducing their anxiety. Therefore, in this study, an interactive e‐book was developed to present the nursing education content to ICU patients' family members. An experiment was conducted to compare the learning performances and perceptions of the patients' family members learning with the interactive e‐book and those who learned with the conventional approach. The research results showed that the nursing e‐book significantly improved the learning performances of the ICU patients' family members, although their anxiety was not immediately reduced. Moreover, the family members perceived that the e‐book was useful and easy to use, and generally showed high satisfaction with its use. This reveals the potential of using interactive e‐books to improve the quality of nursing service in hospitals.