This Tutorial Review aims to provide an overview of the use of zirconium-89 complexes in biomedical imaging. Over the past decade there have been many new papers in this field, ranging from chemistry through to preclinical and clinical applications. Here we attempt to summarise the main developments that have occurred in this period. The primary focus is on coordination chemistry but other aspects such as isotope production, isotope properties, handling and radiochemical techniques and characterisation of cold and labelled complexes are included. Selected results from animal and human clinical studies are presented in the context of the stabilities and properties of the labelled bioconjugates.