He was asked if there had been sharks when he was swimming and if he had bumped into Usain Bolt and Michael Phelps.
He said there were no sharks and he hadn't bumped into the two sporting superstars.
However, everyone in the Olympic village was super friendly.
"They all talk to everyone which is really cool."
He assured the students Rio was not as dangerous as in some media reports, and he and his team mates had felt safe in the city.
When asked by a student who his role model was, Radford said it was NBA star LeBron James for his determination.
He encouraged St Mary's students to never give up.
"If you have a dream, no one can stop you."
Corne van der Merwe, 9, said he thought Radford was really cool and liked that he told them to not give up.
Lina Stahlhut, 11, a member of the same swimming club as Radford, Swim Rotorua, said it was amazing to see Radford in real life.
St Mary's principal David Macmillan said he was humbled Radford came to the school. It was Radford who contacted the school asking to come and thank the students he said.
Radford is currently taking time out from the water, and enjoying relaxing and seeing family and friends.
He was grateful for his Olympic experience and proud of being a Kiwi.
"It's hard to describe the feeling of putting on a silver fern for the first time. You are now in front of the world representing New Zealand."