The performance-related deal with the 31-year-old comes two days before Paranaense take on The Strongest of Bolivia in a Copa Libertadores group match.
Adriano had been in training since December with the team and now he hopes to bounce back after ending an unhappy spell at Corinthians in March 2012.
His last attempt at reviving his career came with a brief 2012 spell at Flamengo which ended in controversy over his fondness for Rio's nightlife.
Flamengo, where Adriano started out as a teenager, cancelled his contract in November 2012 before he had even played and he himself suggested he had spurned his "last chance".
But he insisted Tuesday he was not a spent force.
"It's gratifying to be back, especially after so much hard work and dedication," Adriano told the club's official website.
"I'm going to keep working hard to get game time and do the thing I know best, which is to score goals."
His recent woes are a far cry from the days when the burly forward terrorised Italian defences during his glory years at Inter Milan, where he featured in four Serie A-winning sides.
After initially arriving at Inter from Brazil he was loaned out to Fiorentina, then Parma before returning to the San Siro in 2004.
For the next four seasons his form was volatile. He excelled to begin with before a love of partying and drinking landed him in hot water with club officials.
In November 2007, Inter sent him home to Brazil on unpaid leave and he began a loan period with Sao Paulo which ended in acrimony and an early return to Italy.
After an early burst of goalscoring form at the start of the 2008/2009 season, Adriano returned late to Italy from international duty and Inter cut their ties.
There followed a moderately successful season with Flamengo before he joined Roma. The move proved disastrous, however, and the Italians rescinded his contract after just five games and no goals.
In April 2011, he moved back to Brazil with Corinthians but promptly ruptured his Achilles tendon and the club released him the following year.
At international level, Adriano won the Copa America in 2004 and was tournament top scorer and also landed the FIFA Confederations Cup the following year, also as golden boot winner.
But Adriano's 2006 FIFA World Cup Germany™ was disappointing, netting just twice on the way to a quarter-final loss to France.
The last of his 48 appearances for his country came in March 2010.