The positron-emitting radiohalogens 18F, 75Br, 76Br, and 124I are reviewed regarding their relevance for positron emission tomography (PET) in oncology. Relevant production routes of these cyclotron-generated isotopes are given, followed by publications that deal with applications of these radiohalogens. This article tries to cover the whole literature for the non-conventional isotopes 75Br, 76Br, and 124I. From the literature on 18F, only articles since 2000 are considered. Here, the emphasis is also given to alternative biomarkers beyond [18]2-fluoro-2-deoxyglucose ([18F]FDG).