In the worst attack, two bombs ripped through a square in the central city of Kut, leaving at least 34 people dead and injuring more than 60.
The first bomb exploded at a busy market, followed by a second explosion as rescuers and onlookers gathered at the scene.
In the southern holy Shi'ite city of Najaf, at least four people died when a suicide car-bomber drove his vehicle into a checkpoint outside a police building.
Car bombs, suicide attacks, and gun attacks also killed dozens of people in Tikrit, Kirkuk, Karbala, and Baquba. Bomb blasts in Baghdad, Ramadi, Taji, and Balad also injured dozens of people.
Violence in Iraq has declined from its peak in 2006, but attacks remain common as U.S. troops prepare to pull out.
Under the terms a bilateral security pact, all 47,000 U.S. soldiers currently in Iraq must leave the country by the end of 2011
compiled from agency reports