The 24-year-old amputee swimmer, who lost her lower left leg in a motorcycle accident in 2001, competed in the 10km open-water swim at the Beijing Olympics last month, finishing 22nd.
The South African team thought her mere participation in the games was enough of an achievement to have her carry the country's flag in the opening ceremony.
She showed the same pride in leading the South African delegation on Saturday, and this time she is on a quest for five gold medals, which would equal her haul from the Athens Paralympics four years ago.
She wanted to shoot for six golds, but an administrative error kept her from entering the 100m backstroke on time. She won silver in that event in Athens.
Du Toit will compete in the 50m freestyle, 100m freestyle, 200m freestyle, 100m butterfly and 200m individual medley.