BackgroundAlong with increased online dependency of supplying and obtaining health knowledge, e-health literacy emerges as one of essential skills for people with chronic diseases. ObjectiveThis study aimed to explore the current experience and challenges associated with online health information use behaviors and e-health literacy in middle-aged and older adults, and offer insights for improving e-health literacy level and developing tailored Internet-based health knowledge dissemination services. MethodsFrom June to September 2021, a questionnaire survey was administered to 1 061 middle-aged and older adults in Shanghai communities, using a multi-stage sampling method. The survey instruments included General Information Questionnaire and the Chinese version of the eHealth Literacy Scale (eHEALS). These tools helped measure participants' online health information use behavior and their e-health literacy levels. Multilinear stepwise regression analysis was employed to explore the relationship between internet health information use habits, other potential influencing factors, and e-health literacy levels. ResultsOf the distributed questionnaires, 1,019 were returned, yielding a 96.04 % response rate. In terms of approaches accessing online health information, 40.33 % (411 participants) used health media platform accounts, 32.97 % (336 participants) used search engines, 24.93 % (254 participants) engaged with health management apps or mini programs, and a smaller number, 65 cases participated in online health group. Regarding information sources, a relatively small number of residents relied on medical institutions (38.96 %, 397 participants) and medical personnel (18.35 %, 187 participants). The average eHEALS score was 27.62 ± 8.57. Participants demonstrated limited awareness in using online health information to solve their health problems (item 2 of eHEALS, 3.36 ± 1.27) and in discerning reliable from unreliable health information on Internet (item 6 of eHEALS, 3.38 ± 1.23). Multiple linear regression analysis indicated that e-health literacy was influenced by several factors, including age, coverage of both social and commercial medical insurances, the use of at least two online health information sources and search approaches, behaviors of forwarding and sharing online health information, and holding positive attitude of accepting online health information. ConclusionThe e-health literacy of these middle-aged and older adults is moderate and influenced by various factors, including online health information use behaviors. To help them make better use of online health information and improve their e-health literacy, the authors recommended to provide authoritative information integration and retrieval platform, to strengthen regulation and supervision of health information providers, to develop older people friendly health information online platforms, and to help middle aged and older adults to better use online health information by mobilizing the resources of communities, families, health associations, and medical and insurance institutions.