To travel to the Republic of South Africa you need your passport, which is valid for more than 30 days at the time of return and has at least 2 blank pages to affix the stamps. Argentinean passengers don’t need a visa.
Additionally, if you live in Brazil, Argentina or any endemic zone, you have to present an International Yellow Fever Certificate at the time of Check-in, which proves that you were vaccinated at least 10 days before the travel date.
If you live in Chile, we also recommend taking this certificate, since you could need it in light of any delay or rescheduling of your flight in Brazil and should it involve being in transit for more than 12 hours.
If you’re traveling with a minor, you must also present additional documentation.