The blasts are the latest indication that Iraq's security is rapidly deteriorating as sectarian tensions exacerbated by months of Sunni-led antigovernment protests and the war in neighboring Syria are on the rise.
Iraq has been hit by a wave of bloodshed that has killed more than 300 people in the past two weeks alone.
There was no immediate claim of responsibility for Monday's bloodshed, but the attacks bore the hallmarks of al Qaeda's Iraqi arm. The group, known as the Islamic State of Iraq, frequently uses car bombs and coordinated blasts in an effort to undermine Iraqis' confidence in the Shiite-led government.
One of Monday's attacks happened when back-to-back blasts struck an open-air market in the predominantly Shiite al-Maalif area, killing six and wounding 12 others, two police officers said.
The attack came less than an hour after another car bomb exploded in the busy commercial Sadoun Street in central Baghdad. It killed five civilians and wounded 14 others, two other police officers said. Among the wounded were four policemen who were in a nearby checkpoint.
The street is one of the major hubs in the capital for clinics, pharmacies and shops. Firefighters were seen struggling to extinguish the flames from the debris of the car bomb as police sealed off the area.
Car bombs also exploded in markets in the northern Sabi al-Boor neighborhood, in the southwestern neighborhood of Bayaaa and in Baghdad's central Sadria area, killing a total of 17 people and wounding dozens.
In addition, there were fatal bombings in northern Baghdad's Kazimiyah district, in the eastery Habibiya neighborhood, in the eastern Jisr Diyala area, in the northern Shaab area, and in Madain, about 12 miles south of central Baghdad.