In Brazil, the gradual democratic transition process has generated political institutions with authoritarian characteristics, such as a blurred distinction between internal and external security, as well as a low control under security activities in general. More specifically, the late creation of a Ministry of Defence shows how difficult is to control the military in this country. However, Nelson Jobim’s administration (2007-2011) is an advance comparing to the previous ones, having exerted an effective political authority that has improved democratic civilian control. The National Strategic Defence (2008), the Complimentary Law nº 136 (2010) and the White Book (2012) have contributed for important changes in the Ministry. The objective is to understand the impact of these changes on civil-military relations, based on the concept of democratic civilian control, as well as to identify the reasons behind them. After the civilian aviation crisis, there was a change in the internal State’s balance of power, which helped to consolidated the civilian authority in the Ministry of Defence after Nelson Jobim’s nomination in 2007. In conclusion, a number of factors (personal characteristics, national and international conjunctures and the Executive support) made possible these strucutural changes to happen, which effectivelly created a civilian strucuture in the Ministry.