"The wear and tear of the claycourt season is something that has set me back in the past in terms of the grasscourt season, and the grass is something that I don't want to miss again," the Las Vegan said in a statement.
Agassi's last match was a defeat to German Tommy Haas at Indian Wells in March,
The eight-times Grand Slam champion reached the semi-final at Queen's in 2003 and his decision to play is a major boost for the pre-Wimbledon warm-up event that also includes world number two Rafael Nadal of Spain.
ATP Queen's Club
Hewitt king of Queen's
18/06/2006 AT 14:29
"Andre always brings a little bit of extra magic. His decision to return to Queen's is a wonderful bonus for our spectators," said tournament director Ian Wight.
Defending champion Andy Roddick and three-times former winner Lleyton Hewitt are also playing in the event, which begins on June 12.
ATP Queen's Club
Hewitt aiming to end drought against Blake
18/06/2006 AT 10:34
ATP Queen's Club
Hewitt into 4th Queen's final
17/06/2006 AT 19:34