The principle of equality lies at the heart of most, if not all, public procurement systems. Equality has many facets. One can endlessly drift in the sea of scholarship that has attempted to tackle and define this elusive term. Whether in constitutional law, administrative law, or private law, the equality debate is ever-evolving across all legal domains. It should not come as a surprise then that the concept is far from settled in public procurement law. The principle of equality appears in various stages of public procurement procedures and diverse circumstances. The aim of this article is to review the central notions of equality in public procurement law. This article outlines seven notions of equality arising in various contexts in public procurement law. These notions can help explain public procurement rules and offer reasons why some public procurement systems differ from others. Apart from their explanatory power, these notions can shed new light on current public procurement norms. Revisiting existing public procurement rules through the lens of these notions may tilt the balance they represent and invite normative changes in the scenery of public procurement law.