The attacks continue a surge in bloodshed that has engulfed the country for months. No one has claimed responsibility for Saturday's blasts which targeted commercial areas and car parks in seven cities.
But such organised waves of bombings are used by al Qaida's local branch, known as the Islamic State of Iraq, to undermine public confidence in the Shiite-led government.
The deadliest was in the city of Hillah, 60 miles south of Baghdad, where a car bomb explosion near an outdoor market and car park killed nine civilians and wounded 15 others. A few minutes later, another car bomb went off nearby, killing six civilians and wounding 14.
In the nearby town of Iskandariyah, 30 miles south of the capital, another car bomb hit a car park, killing four civilians and wounding nine.
Another explosives-rigged parked car bomb went off in an industrial area of the Shiite city of Karbala, killing four and wounding 25.
And in Kut, another Shiite-dominated city 100 miles southeast of Baghdad, a car bomb targeted a gathering of construction workers and food stalls, killing two and wounding 14.
There were other attacks in Baghdad and the southern cities of Basra and Nasiriyah,