Boris Pašanski started playing tennis at the age of seven. He already played quite successfully on the Junior Tour and achieved there u. the main draw of three of the four Junior Grand Slams. His best placement was 22nd in March 2000.
In 2001 his career began on the professional tour, where he first played on the third-rate ITF Future Tour . From 2003, after reaching the finals at the Challenger of Ljubljana , he regularly played Challengers , at the end of the year he qualified for the ATP World Tour for the first time . In July 2004, Pašanski won his first challenger in Tampere .
2005 was the Serbs' most successful year, he won a total of five Challengers and was in another four finals, so that he moved into the top 100 in the individual world rankings . Due to his improved ranking he was able to play tournaments on the ATP World Tour . At first he was able to achieve good results there too - three quarterfinals in a row and his career high with rank 55 - but then he hardly won any matches and had to compete again at Challengers. Nevertheless, Pašanski played in all four Grand Slam tournaments in 2006, although he only survived the first round of the 2006 Australian Open in his career . In doubles he also reached his only final of the World Tour in Buenos Aires .
In 2007 he won the last of his seven Challenger titles in singles and was able to finish the year in 95th place. As a result, he mainly played Challengers and slipped in the world rankings continuously, so that he also had to fight his way through the qualification at Challengers. He got a surprise in Naples in 2010 when he defeated top 50 player Potito Starace in Naples and reached the final. In October 2014 he ended his professional career after his defeat in the qualification of Geneva .
In 2003 he made his debut for the Serbian Davis Cup team . In total, he was appointed to the team six times and played nine singles, of which he won six. It was last used in 2013.
In November 2017 it was announced that Pašanski would be the new coach of his compatriot Viktor Troicki .