Speaking for the first time in person about the IAAF's gender tests that have sidelined her since the world championships last August, the 19-year-old South African was defiant in saying she would decide her future on the track, no matter what the results are of the tests that are expected in June.
"When I came to athletics I am the one who decided to run," Semenya said. "I'm the one who decides. They (the IAAF] can make their own decisions. But don't forget I am the one who must say so. I will decide if I walk out or if I stay there."
When asked if she had thought seriously about giving up, Semenya smiled and said no. "I don't quit," she said.
Semenya called the press conference to launch the Caster Semenya Sports Academy and appeared alongside coach Michael Seme. But in her first public appearance since she was prevented from taking part in a meet in Stellenbosch in March, Semenya cast doubt on her long-term future in athletics. "I can not do it for a living," she said.
"Athletics is athletics. When you do sport you are gambling. You run, you win, you lose. It doesn't matter if you are competing or you are not competing."
Semenya is studying at the University of Pretoria and said she had other options. "To me, I don't think sport is something that I can take for life. I still have my academy, my studies. I cannot say athletics is my first option."
Semenya's comments hinted at her frustration at the lengthy IAAF process. She has not competed since her stunning debut at the world championships in Berlin, where she blew away the field in the 800-metre final. It led to the IAAF ordering gender tests for the runner, who was 18 at the time.
Semenya began the news conference by thanking her advisers, coach, family and people of South Africa for their support. "They've been good to me," she said. She also said "the scandals, I can't talk about now because we are concentrating on the academy and the website."
Semenya also said her goal, through the academy, was to help talented athletes who came from "humble" backgrounds, like her. "We are going to help the young talented athletes become world champions," she said.