Academia, the International Integrated Reporting Council (IIRC) and the International Auditing and Assurance Standards Board (IAASB) have revealed that making the integrated report subject to an assurance engagement is necessary to satisfy stakeholders’ demands for credible and reliable documents, which will guarantee market stability and support organizations in a sustainable way to improve their operational performance. Even though the proportion of integrated reports that are assured remains low, the procedures followed for their assurance have swiftly gained prominence. In both academic and professional sectors, these assurance procedures are now considered one of the auditing innovations of recent decades. However, there are several issues that concern researchers, standard setters, and practitioners. This chapter will provide insight into this emerging field, by analysing the state of play of assurance practices, current issues, and future challenges and research opportunities.