The 33-year-old, who recently left German club VfL Wolfsburg, will be paid a minimum 500 zloty (102 pounds) salary which he has agreed to give to charity.
Blaszczykowski, who has more than 100 international caps, started his career with Wisla before spending nine years at German club Borussia Dortmund and helping them win two Bundesliga titles.
He has lent financially-troubled Wisla Krakow 1.33 million zloty.
Wisla this month sold 4 million shares for 4 million zloty on a crowd-funding platform to their fans, who now own about a 5 percent stake in the club.
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(Reporting by Marcin Goclowski, editing by Ed Osmond)
