The last quadruple-double in the NBA occured on February 17th, 1994 when the San Antonio Spurs hosted the Detroit Pistons. During the game, the Admiral, David Robinson, recorded 34 points, 10 rebounds, 10 assists and 10 blocks for a quadruple-double. It's almost a little too-perfect a stat-line, but still impressive. Robinson would win the MVP award the following year.
Interesting follow-up. In the last regular season game of that year (93-94), Robinson would score 71 points to snatch the scoring title from Orlando Magic center, Shaquille O'Neal. Robinson needed all 71 of those points as the two big men were only separated by 6 points after the game. Shaq finished with 2,377 points in 81 starts, and Robinson finshed with 2,383 points in 81 starts after his explosion for 71.
*The more you know, the bigger NBA nerd you've become*