Zinsli started skiing at an early age. At the age of 3, he tied his first skis to his feet and tried to ski on the local mountain. At the age of 7 he won the annual Chur school ski race and was discovered there by the Ski Club Rätia Chur and asked whether he would like to ski in this club in the future. In doing so, he laid the foundation for his future professional career. Thanks to consistently good performances at the Chur Ski Club, Andrea Zinsli was able to ski pretty quickly for the Bünder Ski Association and continued to develop steadily. At the age of 16, the door was opened to him for the Swiss-Ski C-team , to which he was a member for around 4 years. At the age of 20, he was appointed to the B-team and only one year later he was appointed to the Swiss-Ski national team.
At the age of 25 years, Andrea Zinsli buckled at a football match in physical training so unfavorably with the foot in order that he is doing a bursitis drew upon. The inflammation did not develop as expected, so he caught an infection in the hospital . Meanwhile, Andrea Zinsli had to give forfait for the entire 1997/98 season in order to fully concentrate on his injury and his recovery. In the 1998/99 season Andrea Zinsli drove his last races for the A-squad before he was transferred to the C-squad of Swiss-Ski for the next 2 years. In 2001, at the age of 29, Andrea Zinsli announced his retirement from top-class sport, as he could no longer return to his old level after his injury.