The lower house of parliament voted 319-73 with 195 abstentions in favor of the plan. Representatives of Germany's 16 states raised no objections in the upper house later Friday - meaning that the chamber passed the bill.
It now goes to President Horst Koehler for his signature - expected to be a formality.
The euro750 billion (nearly $1 trillion) package was drawn up two weeks ago.
Germany, Europe's biggest economy, will contribute between euro123 billion and euro147.6 billion in loan guarantees. It comes soon after a separate package to rescue Greece - which was already unpopular, given that Germans dislike the idea of paying for others' financial missteps.