Benedict will say an open-air mass on Sunday which half a million people are expected to attend.
Benedict called on Africa to show "a determination born from the conversion of hearts to excise corruption once and for all.
"Unfortunately within the borders of Angola there are still many poor people demanding that their rights be respected. Do not disappoint their expectations," he said in his televised address.
Benedict called for "respect and promotion of human rights, transparent governance, an independent judiciary, a free press, a civil service of integrity, a properly functioning network of schools and hospitals".
Many of those are still lacking in Angola where two-thirds of the population still live on less than $2.
A long civil war, which claimed over half a million lives and displaced millions, only ended in 2002.
Since then Angola's economy has grown because of its oil and diamond exports, but is still suffering from corruption.
The country was ranked by Transparency International, a German-based organisation that highlights corruption, as among the most corrupt in the world.
The Catholic church is one of the few strong voices outside of Angola's government, with 55 per cent of the population being Catholic.
In his speech in Angola, Benedict criticised part of the African Union's charter that gives women a right to an abortion in cases of rape, incest or major health risks to the mother,
He said abortion was not a health issue.
Benedict's Africa visit has been overshadowed by his rejection of condoms in Aids prevention and his reiteration of the church's ban on abortions, even in cases where the mother's life is at risk.
In remarks made on Tuesday, Benedict said that Aids "cannot be overcome through the distribution of condoms, which even aggravates the problems".
This led to anger amid Aids activists as well as some governments, who said that Benedict's remarks could harm Aids-prevention campaigns.
Angola is one of the countries where the government is carrying out a massive nationwide campaign to promote condoms.