International Encyclopedia of Public Health, 2nd edition, Volume 3Advancements in information and communication technolo- gies (ICTs) including Internet have accelerated the search for health-related information and become a common practice worldwide. It has brought a change in people’s lifestyle and has a greater impact compared to any other communication tools. A study by Alghamdi and Moussa (2011) noted that, a majority of people rely on Internet to search for health infor- mation, social, business, and other information available online. The evolution of Internet and its utilization has improved access and retrieval of health information. Alghamdi and Moussa (2011) observed that patients used various sources of information such as newspapers, books, and colleagues to search for health information in previous days. Modern search engines and platforms (e.g., social networks, websites, portals, health databases) have made health information easily acces- sible using various devices such as smart phones, tablets, laptops, and computers (Hong et al., 2015). Health informa- tion is now available at fingertips. The Internet is a powerful tool for empowering patients in making decision on health-related matters, and it facilitates patients to communicate easily in health-care services. It is also observed that limited patient communication is associ- ated with poor patient health outcomes and low patient satisfaction. However, Internet is viewed as a medium for patient empowerment; although some websites are not rated as trustworthy or validated (Beck et al., 2014). The public health impact of the Internet is wide reaching, affecting many aspects of people’s social lives and practice. For example, university students used the Internet to search for health information on various aspects especially on specific illness, fitness, and nutrition compared to other online users. In higher learning institutions and health-care centers, Internet has been a crucial tool in exchanging information using various online platforms such as social media tools (e-mails and other interactive tools). Telemedicine and video conferencing are useful tools in transferring information from one part to another (e.g., in facilitating hospital communication) in relation to clinical aspects such as medical diagnosis, treatment, transferring of data, and moni- toring patients’ health-care delivery services. This article focuses on the use of Internet for public health, and it covers the following subtopics: accessibility, quality, prospects, efficacy, and challenges of accessing health informa- tion on the Internet.