The milk sector across the European Union (EU) has experienced several changes, due to the intrinsic characteristics of its respective structures of production. In fact, due to significant increases in production, this sector has suffered dramatic surplus supplies, which have had a relevant impact, namely on the market’s management. In this framework, the EU created the milk quota system in the 1980s to control the milk markets and prepare the sector for the subsequent reforms verified by the agricultural policy instruments. However, this system was a temporary measure from the Common Agricultural Policy (CAP) and was removed in 2015, having new and relevant impacts on the sector around Europe and, specifically, in Portugal. In this context, the main objective of this research was to assess the several impacts from the several reforms of the CAP instruments for the milk sector within the Portuguese context. For this, a literature survey from the Web of Science (Core Collection) was carried out searching for the topics “milk” and “Common Agricultural Policy.” From this search, 57 documents (only articles were considered, excluding, for example, proceedings papers) were obtained. To complement this literature review, several data from the Eurostat and from the Portuguese agricultural market information system were considered and explored through econometric approaches. The main insights obtained show that the milk sector is a controversial topic, which continues to need special policy attention, namely to avoid asymmetries across the several EU member-states.