Corrosion of the reinforcing steel in prestressed concrete (PC) structures is a major durability and safety concern, especially in concrete bridges where the presence of high-strength prestressing steel and deicing salts may lead to stress corrosion cracking. Several collapses of prestressed concrete bridges have shown the vulnerability of these structures. Despite the high risks, there is a lack of effective inspection and monitoring techniques for assessing the hidden corrosion process that initiates internally in concrete, ducts and joints. A most promising technique for detecting corrosion cracking and wire breaks is the acoustic emission (AE) technique. This monitoring technique enables localization and characterization of internal damage sources through the detection of ultrasonic elastic waves that are produced by the ongoing damage process itself. The objective of this review paper is twofold: firstly, the effectiveness of AE monitoring for assessing critical corrosion processes in prestressed concrete is investigated by means of a comprehensive study of experimental data reported in the literature. Although many experimental studies have focused on this issue, there is still a lack of coherent data that allow confident upscaling of AE results to complex and heterogeneous PC structures. Further, from an analysis of case studies reported in the literature, a lack of scientific literature on field monitoring applications is found. Therefore, a second objective of this paper is to study two recent case studies, bridge 55b (Döbeln) and the Carola bridge (Dresden), in which AE monitoring was applied to support decision making in view of corrosion risks.