List of 5X5's in NBA history
According to several unofficial box scores of the time, Wilt Chamberlain recorded 3 quadruple doubles in the playoffs in the 1960s. Blocks and Steals were not officially kept by the NBA until 1972, so while these quadruple doubles may have happened they are not official. Here are the 3 Chamberlain unofficial quadruple doubles.
Year Game Opp PT RBS AST BLK
1967 EDF GM1 vs Celtics 24 32 12 12
1967 NBA Finals GM2 Warriors 10 38 10 10
1968 Regular Season Pistons 22 25 21 12
1970 WDSF GM6 Lakers 12 26 11 12
Chamberlain's nemesis, Bill Russell may have even one upped Wilt. In 1961 Russell posted what would be the earliest known quadruple double and if they were recorded, would be the still standing steals record.
Year Game Opp PT RBS AST STL
1961 Regular Season Warriors 15 25 13 15
It is very likely that there are several more unofficial quadruple doubles out there that have just been forgotten by time. If you have found any please let us know at firstname.lastname@example.org