Vilim was born on July 3, 1986 in Mali Lošinj, Croatia. He started playing tennis at the age of 3. Vilim is a four-time Croatian champion and ranked second in Europe on the EA16 list. As a junior player, he was ranked 21st in the world by the ITF. As a junior player he competed at the Australian Open, Roland Garros and Wimbledon. The best result at Roland Garros is the second round of the competition. Vilim has also played at Wimbledon, where he entered the second round. In addition, Vilim Višak played doubles with Novak Djoković in a quarter-final match at Roland Garros, and was a sparring partner for Bernard Tomić. His career highs were 612th place in the ATP singles rankings and 370th place in doubles. He is a four-time champion of the Croatian Tennis League (including 2013).
As a coach, Vilim has achieved excellent results:
- With Joseph Messina he won the Croatian championship for players up to 18 years old;
- With Gordan Brkić, he won the Croatian championship for players up to 18 years old;
- He worked one year in the Vajda-TudorTennis Academy;
- He is currently training Petra Ivanišević who is ranked eighth in Croatia in the category for players up to 12 years old;
- He is training Leopold Mužić who is 62nd in Croatia in the category for players up to 18 years old;
- He has been a manager and coach in Čikat Tennis Centre since 2011.