Over the past few decades, substantial work has been carried out by researchers in the field of unethical employee behaviour. While self-interest is a more focused area of research, recent studies have investigated pro-organisational unethical behaviour. Furthermore, it is known that unethical behaviour often occurs beyond the realm of conscious awareness. At present, a comprehensive review of unethical employee behaviour that explicates the various types of unethicality is still lacking. In this study, we perform a literature review and integrate the studies under the dimensions of self-interestedness and intentionality. Consequently, four distinct patterns of unethical employee behaviour emerge, which we classify into a typology comprised of four types: (1) unethical pro-self behaviour-explicit, (2) unethical pro-self behaviour-implicit, (3) unethical pro-other behaviour-explicit and (4) unethical pro-other behaviour-implicit. We contend that each of these behaviours consists of different psychological processes, discuss the individual and situational determinants of each typology and tabulate key findings. Overall, we find that the field will significantly benefit from additional impetus being placed on the under-investigated areas of unethical employee behaviours, which, according to our defined typology, includes the implicit and the pro-other types. © 2020 Informa UK Limited, trading as Taylor & Francis Group.