The 26-year-old’s new deal will keep him at the Signal-Iduna Park until the summer of 2016.
Blaszczykowski has been linked with the likes of Liverpool and Manchester United in recent months.
He told his club’s official website: “I am very, very happy about the new agreement.
“There are not many clubs out there who have such a large fanbase and there are also not many clubs who have been able to do what we have achieved in the last two league seasons.
“It is great to remain a player of this big club Borussia Dortmund.”
Dortmund general manager Michael Zorc said: “We are delighted to have agreed new terms with Kuba (Blaszczykowski).
“Kuba has shown in the most recent Bundesliga season why he is such an important player at our club. Kuba also has the Dortmund emblem very much stored in his heart.”
