5. Cleveland Cavaliers (1981-83) - 24 games
Over the course of the 1981-83 NBA seasons, the Cleveland Cavaliers would stack together a 24-game losing streak - losing 19 games to end the 1981-82 seasons and then five games to start the 1982-83 season. Together, that equates to one of the longest regular season losing streaks in NBA history. During those two seasons, the Cavs were one of the worst teams in the league. During the 1981-82 season, the Cavs finished with just 15 wins. During the following season, they didn't fare much better and won just 23 games.
It would take a few years for Cleveland to recover and put together a competing team in the Eastern Conference. Starting during the 1984-85 season, Cleveland would manage to make the NBA Playoffs 10 times in the next 14 seasons. They would also go on to make one conference finals during the 1991-92 season.
Up to that point, it was one of the more successful eras for the franchise. But, make no mistake, the losing in the early 1980s was certainly tough for the fanbase to swallow - even for the young franchise.