The Dodgers acquired Marmol along with about $2.5 million and about $209,000 in relief from the international signing limits from the Cubs in exchange for Matt Guerrier on July 2, a week after the Cubs designated Marmol for assignment.
Marmol had been working his way back in the minor leagues. He allowed a pair of home runs for Single-A Rancho Cucamonga in three innings of work and pitched two hitless innings at Chattanooga.
Marmol likely will pitch in middle relief for the Dodgers, who are set at closer with Kenley Jansen.
The Dodgers placed young reliever Jose Dominguez on the 15-day DL with a left quadriceps strain to clear room for Marmol.
Marmol was 2-4 with a 5.86 ERA and 32 strikeouts in 21 games for the Cubs this season.
Since 2007, Marmol leads major league relievers with 644 strikeouts, 117 more than his closest competitor, Jonathan Papelbon, and ranks fourth with a .174 opponents' batting average. He has accrued 20 or more saves in each of the past three seasons, including a career-high 38 saves in 2010.