Almost a third of construction sites in the East Midlands failed safety inspections during a recent 'blitz' by the Health and Safety Executive (HSE).
Inspectors from the HSE carried out checks at 137 construction sites across Nottinghamshire, Derbyshire and Lincolnshire during March.
They issued a total of 44 enforcement notices, either stopping work immediately or requiring improvements to be made. The majority of the notices covered unsafe work being carried out at height.
Two sites, one in Lincolnshire and one in Derbyshire, are still under investigation with a view to being prosecuted.
Nic Rigby, HSE's principal inspector of construction for Nottinghamshire said: "The majority of the construction sites our inspectors visited had good health and safety procedures in place. But the other sites are letting the rest of the industry down and putting workers' lives at risk.
"HSE will not tolerate poor health and safety standards on construction sites and we will continue to make unannounced visits and take enforcement action when necessary, until the message gets across. It simply isn't worth taking risks to try and save money.
"Companies have a legal responsibility to protect the lives of workers and site safety should be paramount."
Latest figures from HSE show there were 227 serious injuries on construction sites in Nottinghamshire last year, 162 in Derbyshire, and 113 in Lincolnshire.
The intensive inspections took place as part of a month-long initiative aimed at stopping dangerous practices on building sites across Great Britain.
HSE wants to raise awareness of construction site risks to prevent deaths and injuries in the future. Construction is one of Britain's most dangerous industries, with one death and 777 serious injuries in the East Midlands during 2008/9.
Last year inspectors visited 1759 sites and 2145 contractors and were forced to issue more than 270 prohibition notices to stop dangerous work - much of it relating to working from height.