Ze Roberto, who turned 37 last Wednesday, goes to Qatar on a free contract having only been offered a one-year extension to his deal at Hamburg after joining the north German club in July 2009.
The Brazilian has the record for the most appearances by a foreigner in German league history with 336 games in a career which has taken him also to Bundesliga clubs Bayern Munich and Bayer Leverkusen.
In Qatar, the Brazilian will replace compatriot Juninho, 36, who is returning home to play for Rio de Janeiro club Vasco da Gama after two seasons with Al-Gharafa.
Ze Roberto quit Bayern in 2009 to join Hamburg having also been offered just a one-year extension to his deal with the Bavarian giants.
In a 12-year international career, Ze Roberto won 84 caps for Brazil between 1995 and 2007.