An anti-gay bill passed by the Ugandan legislature prompted more than 200 people, including LGBTQ activists, to demonstrate outside the Ugandan High Commission on Tuesday.
The protest was led by the left-wing South African opposition party Economic Freedom Fighters.
The party called on Ugandan President Yoweri Museveni not to sign the bill.
The demonstrators called on the South African government to speak out against the bill, which they say threatens the freedoms and security of the LGBTQ community in Uganda.
The bill, passed by 389 Ugandan legislators, provides for severe penalties for homosexuality, including the death penalty and a 20-year prison sentence.
The passage of the bill has been condemned by the international community and the United States, which has threatened to impose economic sanctions on Uganda if the bill is enacted.