Rode has struggled to make an impact since joining Dortmund from Bayern Munich in 2016.
The midfielder last appeared in the Bundesliga in May 2017 and will spend the rest of the campaign on loan with Eintracht, where he played between 2010 and 2014.
"We thank Sebastian Rode for his commitment to this day and wish him much health and match practice for his time at Eintracht," said BVB sporting director Michael Zorc.
Rode has been out of action with a groin injury, but the 28-year-old declared he is ready to make an impact on his Eintracht return.
"I am very happy to be able to attack fully again," he told Eintracht's website. "I have the time in harmony and above all the team is in very good shape and they have a lot to plan for the next six months and of course I want to do my part."
Dortmund are six points clear at the top of the Bundesliga going into the mid-season break, with Eintracht in sixth spot, and sporting director Fredi Bobic feels Rode's arrival will be a boost.
"We are confident that the quality of the squad will be further enhanced with Sebastian, an absolute team player, who has gained a lot of experience at Bayern and Dortmund in the past four years and will now benefit us," said Bobic.
"Sebastian is a very good fit in our team and we've been looking at him over the past few weeks and months to find he has completely overcome his injury, and we believe this solution is a win for all parties.
"Sebastian Rode has shown his potential in the past, if he stays injury free, he will be able to help us, he wanted to join us and did his bit to make it happen."
Eintracht will return to Bundesliga play when the league resumes in mid-January with a home date against Freiburg.