236 unlicensed taxi-drivers have been prosecuted since the beginning of last year.
There were 178 in 2018 - 56 more than the year before.
According to details released under Freedom of Information, most taxi-men didn't have the driver or vehicle licences required.
A former vice-president of the National Taxi Drivers Union, claims many more operators are flouting the law.
There are calls for greater enforcement by the Gardaí.
