It has been recognized that sharing data between organizations can be of great benefit, since it can help discover novel and valuable information that is not available in individual databases. However, as organizations are under pressure to better utilize their large databases through sharing, integration, and analysis, protecting the privacy of personal information in such databases is an increasingly difficult task. Record linkage is the task of identifying and matching records that correspond to the same real‐world entity in several databases. This task implies a crucial infrastructure component in many modern information systems. Privacy and confidentiality concerns, however, commonly prevent the matching of databases that contain personal information across different organizations. In the past decade, efforts in the research area of privacy‐preserving record linkage (PPRL) have aimed to develop techniques that facilitate the matching of records across databases such that besides the matched records no private or confidential information is being revealed to any organisztion involved in such a linkage, or to any external party. We discuss the development of key techniques that solve the three main subproblems of PPRL, namely privacy, linkage quality, and scaling PPRL to large databases. We then highlight open challenges in this research area.This article is categorized under: Algorithmic Development > Association Rules Commercial, Legal, and Ethical Issues > Social Considerations Fundamental Concepts of Data and Knowledge > Data Concepts Technologies > Data Preprocessing