The People's Movement for the Liberation of Angola (MPLA) is leading the race with 52.08% of the vote after 86.4% of ballots were counted.
The opposition National Union for the Total Independence of Angola (UNITA) is second with 42.98%. The remaining six parties are each on 1% or less.
Whichever party wins the August 24 elections also appoints the next president. Incumbent Joao Lourenco is from MPLA, which has been in power since the southern African nation won independence from Portugal almost half a century ago.