Nikola Pilic became known in the 1973 boycott of Wimbledon: in that year the Yugoslav tennis federation declared that Pilić had refused to represent it in the Davis Cup. Pilić denied what was contested but was still suspended by his federation, a suspension also supported by the ILTF.
This meant in practice the exclusion of him from major tennis tournaments. In reaction to this decision, eighty-one professional friends of Pilic withdrew from Wimbledon.
After retiring Pilić became a coach and was the first captain to win the Davis Cup for two different nations, namely Germany (in 1988, 1989 and 1993) and Croatia (in 2005). He also helped Serbia win the Davis Cup in 2010 as a technical adviser. Pilic was also the first coach of Serbian player Novak Dokovic, later world number 1.