The 1986–87 Seattle SuperSonics season was the 20th season of the Seattle SuperSonics in the National Basketball Association. Bernie Bickerstaff returned for his second season as head coach of the franchise and, despite a modest improvement over their previous season's 31–51 record, managed to clinch a spot in the playoffs, where they defeated the Dallas Mavericks in four games in the First Round, and then the Houston Rockets in six games in the Semi-finals, reaching the Western Conference Finals, only to be swept in four games to the eventual NBA champion Los Angeles Lakers. The 39-43 Sonics remain the last team to date in the NBA to win a playoff series with a losing regular season record.