Closely supervised by police, some 4,000 people marched peacefully with banners criticising the ruling People's Movement for the Liberation of Angola (MPLA) and President Joao Lourenco, according to an AFP reporter.
The protest was organised by the National Union for the Total Independence of Angola party (UNITA), whose popularity has been growing in recent years.
UNITA rejected its loss in the 2022 election and challenged the outcome in court, but the country's top court dismissed the petition.
"Lourenco leave" one banner in Saturday's march said, while others claimed "people are dying of hunger" and described the government as a "dictatorship".
Many marchers wore the opposition's red and green colours as they passed through the streets under the close watch of police, including officers on horses.
Lourenco has governed Africa's second-biggest oil producer since 2017 and has often been accused of authoritarianism by his opponents.
UNITA's secretary general Alvaro Chikwamanga told AFP that the march was to protest against "bad governance".
"Angolan people are dying of hunger, children are malnourished and eating from the bins, all the while our country is rich in resources," he added.
Among the demonstrators, Elisabeth Ana Bela, a 24-year-old student, said she joined the march because "famine is a huge issue".
"Things have to change," she said.
A record drought has devastated crops across southern Africa, causing millions of people to go hungry, the UN has warned.
Another young protester, 18-year-old Jose Venancio, blamed the ruling party for the country's problems.
"Our country has lost all value... famine has become a war, and the MPLA isn't serious about improving people's lives," he said, adding he was "happy and proud" to be part of the march.
UNITA, a former rebel group now the second largest party in the country, invited civil society and other opposition groups to join the protest including from the United Patriotic Front.
While the MPLA was re-elected with 51 percent of votes in the last election, UNITA followed closely behind with 44 percent.
