Isiah Thomas had a triple-double in Game 4 of the 1989 Eastern Conference Semifinals versus the Bucks on May 15, 1989.

isiah thomas last triple-double
Not what you're looking for?
NAMEDATETMOPPTD3MINPTSREBASTSTLBLKTOVFGMFGAFG%3PM3PA3P%FTMFTAFT%PF+/-
Isiah ThomasIsiah Thomas5/15/1989
DETDET
@
MILMIL
14017101301371450.022100.01250.03
Isiah ThomasIsiah Thomas2/1/1987
DETDET
vs
CHICHI
14014111311441233.3006875.03
Isiah ThomasIsiah Thomas11/28/1986
DETDET
vs
MILMIL
1371211151011714.3020.01010100.02
Isiah ThomasIsiah Thomas4/25/1986
DETDET
vs
ATLATL
153301012103132944.8010.04944.44
Isiah ThomasIsiah Thomas2/7/1985
DETDET
@
WASWAS
15025102421292733.31333.36966.71
Isiah ThomasIsiah Thomas1/5/1985
DETDET
@
WASWAS
14227111340282138.111100.0101376.93
Isiah ThomasIsiah Thomas2/8/1983
DETDET
@
SASSAS
146461011401142458.33560.0151883.32
StatMuse has game-level data for triple-doubles going back to the 1950-51 season.