Abstract Wireless communications have gained huge attention over the past decades because of continuously increasing demands. The main goal of all wireless network designers is to utilize the spectrum efficiently. Many techniques have been introduced to tackle this. One of these techniques is Cognitive Radio Technology, which allows unlicensed users to utilize the neglected spectrum by operating alongside with the licensed users. In-Band Full-Duplex (IBFD) technology is another technology that has allowed wireless devices to communicate simultaneously in the same frequency band, which also efficiently increased the utilization of the spectrum. The implementation of these two technologies in unison has been attracting researchers’ interests in recent years. The main concentration of this work is to survey IBFD Cognitive Radio Networks (IBFD–CRNs) from the perspective of each layer, namely the Physical (PHY), Medium Access Control (MAC) and network layers. The key objective of this work is to help the research community in understanding the big picture of this field, starting from the very basics of cognitive radios, then going through recent advances of IBFD communications with coverage of several Self Interference Cancelation techniques and finally ending with discussing the basic concepts of IBFD–CRNs along with providing some future research directions.