This article has the objective of emphasizing the most relevant aspects of the productive milk chain in Brazil. The work is descriptive and was done through bibliographic research based on specialized literature on dairy activities and economics. The study showed that the external environment has a great significant influence in the competitiveness of the national dairy sector, on account of a set of political and economical factors and on those that are related to the legislation and regulation, about which the productive chain agents have little or almost none power of intervention. It also showed that these factors cause a series of distortions resulting either from public polices intrinsically domestic, or subsidized ones adopted by the European Union and the United States. Finally it is concluded that this set of factors, external to the dairy chain, has been decisive for the competitiveness in this sector and for those direct or indirect involved in the activity or for those representing the public power. Key words: milk, productive chain, external environment.