A hundred-and-twenty-eight fines were issued by Gwent Police as part of a crackdown on mobile phone use behind the wheel.
Across Wales, nearly 1,000 motorists were caught using their mobile phones during a two-week campaign last month.
Officers from all Welsh police forces carried out patrols to target motorists using their mobiles.
In the Gwent area a total of 128 fixed penalty notices were issued, while South Wales Police issued 242 notices to law-breakers.
In the Dyfed Powys force area 454 notices were given, while in North Wales a total of 148 offenders were caught.
Gwent Police Roads Policing Inspector, Lee Ford, said: “This campaign is just one part of our ongoing effort to target and reduce the number of drivers who risk becoming involved in a serious or fatal collision due to using a mobile phone while driving.
“Along with drink driving, speeding, not wearing a seatbelt and driving carelessly, using a mobile phone behind the wheel, whether it be texting, using an app, or making a phone call is classed as one of the “Fatal 5”; the 5 most common causes of fatal road traffic collisions.
“Even the most experienced or competent of drivers can be easily distracted. A slight lapse in concentration can have serious consequences and it is disappointing that 128 motorists in Gwent have broken the law and risked their own lives and the lives of others.”
Susan Storch, Chair of Road Safety Wales added: “We all need to take account of how we drive on our roads and driving a vehicle requires us to multi-task so anything above and beyond that needs to wait until we are safely parked up or until our journey has finished.
“While it’s saddening to see that so many motorists got caught using a mobile phone whilst driving it has also demonstrated the resolve of all the Road Safety Wales partners in tackling this issue and we will continue to work together to drive home the message that you need to switch off before you drive off.”