[1] Following this, from 1962 till 1965, Brünner was departmental head in the Political Central Administration of the East German Ministry for National Defence.

Brünner was able to celebrate the twentieth anniversary of the National People's Army with another promotion in March 1976, this time to the rank of lieutenant general.

In 1985 he succeeded Heinz Kessler as Deputy Minister for National Defense and Chief of the Central Political Administration.

Horst Brünner was one of only eleven officers to be promoted to this level during the lifetime of the German Democratic Republic.

In the early summer of 1998 the Berlin Regional Court sentenced Brünner, along with his co-accused Manfred Grätz, Wolfgang Herger and Heinz Tappert, to a two-year suspended jail term.