"I have decided to change my decision and confirm my availability to play for the Black Stars whenever I am needed," Boateng wrote in a letter to the Ghana Football Association, who released copies on Friday.
Ghana have written back welcoming his decision, even though the 26-year-old cold shouldered them after the 2010 World Cup.
The Ghanaians are on the cusp of a place at the 2014 finals in Brazil, needing a draw in their last group game to go through to the final round playoffs in October and November.
Boateng was born in Germany to a Ghanaian father and German mother and switched allegiance after playing for the Germans at junior level, making his debut for the Black Stars just weeks before the 2010 World Cup finals in South Africa.
In November 2011, however, as a potential five-week absence from his Italian club for the African Nations Cup finals loomed, he wrote to the GFA telling them he no longer wanted to play international football, claiming the physical demands of playing for both club and country were taking a toll on his career.
He also missed the 2013 Nations Cup finals. In both tournaments, Ghana reached the semi-finals.
Boateng, who has nine caps, now becomes available for the qualifier against Zambia on Sept. 6, where a home draw will see Ghana advance to the last stage of African qualification.