Bence Mocsári was born without an elbow joint in his left arm. He started swimming at the age of six because of his health issues. However, when school started he gave up swimming.
Six years later, in 2012 he was watching the London Paralympic Games when he decided to become a Paralympic Champion. He began swimming again and became multiple time Para World Series medalist, Hungarian Champion and in 2017 he became fifth in 200m IM in Mexico at the World Para Swimming Championships. He was always good at running in the dry land training sessions and in 2018 his coach and the Hungarian Triathlon Union persuaded him to become a triathlete.
In 2023 Bence moved to another city in Hungary where he continues his professional preparation in collaboration with his new coach Szilard Toth. This change has proven to be successful as it is reflected in Bence’s results. 
His goal is to take part in the 2024 Paris Paralympic Games.