The 26-year-old has scored 18 goals in 48 appearances since joining from Dinamo Zagreb in 2007 but his time in north London has been overshadowed by a career-threatening leg break early in 2008 that ruled him out for nearly a year.
"We're delighted Eduardo has signed a new long-term contract with us," manager Arsene Wenger told the club's website.
"Eduardo is a special player with huge talent and natural goal-scoring ability and we're all so happy he has committed his future to Arsenal.
"We have also seen in his comeback from injury, Eduardo is a human being full of courage, bravery and commitment. His full recovery from this injury is a testament to Eduardo's character," added Wenger.
Eduardo said he felt fully recovered from the injury and was ready to repay the club's faith in him.
"I'm very happy and I hope to stay at Arsenal for as long as I can," said the striker. "This period is good for me.
"I feel strong in my body and I feel ready to play 90 minutes every three days if it's needed.
"I went to Croatia last week and everybody was telling me Arsenal play the best football in Europe at the moment. I agree with that. We feel we are strong now this season and we're all going to give everything to win trophies," added Eduardo.
