During the Rhodesian Bush War, he served on the ZANU high command, or Dare reChimurenga as Treasurer (dura remusangano). When Nkala and most of the nationalists within the leadership were imprisoned, Paul Tangi Mhova Mkondo took over the role. Nkala was detained by the Rhodesian government at Gonakudzingwa for 12 years with the rest of the ZANU-PF (formed in Nkala's house in Highfields) leadership, consisting of Ndabaningi Sithole, Leopold Takawira, Robert Mugabe, Edgar Tekere and Morris Nyagumbo. When Edgar Tekere was in prison, he tabled the motion of having Sithole removed as the supreme leader and replaced by Mugabe. Nkala and Nyagumbo voted in favour of Mugabe (Mugabe abstained), making him leader.