Domain-specific search engines only index documents relevant to a specific domain, such as health information or intellectual property information. As prior knowledge is available about the domain of interest, such search engines can be adapted to take advantage of this knowledge for improving search results. Furthermore, the users of these search engines often have specific requirements as to how the search engines should function. This course begins with a general introduction to domain-specific search and the methods used, such as adapting vector space weighting and using specialized vocabularies. This is followed by more detailed coverage of two domains. In web search for health information, the quality and trustworthiness of the information is extremely important, as is the readability level – will this information be understood by a layperson or only by a medical professional? In the intellectual property area, professional patent searchers are faced with the task of finding all patents related to a query (high recall), even though patent documents are sometimes not written to be found easily. In both of these domains, image search is also extremely important. Finally, after an overview of evaluation, evaluation campaigns and their results in the area of medical information search and intellectual property search will be discussed.