The blast killed 51 people and wounded at least as many others, Gen. Saad Maan, spokesman for Baghdad's Operations Command, said in a statement.
The attack targeted a busy car market in the predominately Shia al-Bayaa district of the Iraqi capital, a security official said.
The explosion came less than a day after another car bomb rocked eastern Baghdad, killing five people and wounding at least 20 others, according to Saad Maan, spokesman for Baghdad's Operations Command. That attack happened in the predominately Shiite neighborhood of Habibiya, he said in a statement.
Car bombs and roadside bombs are not uncommon in Baghdad, but in 2017, ISIS has already carried out several attacks across the capital and killed dozens of people.