The Court of Appeal has said the use of breathalysers to arrest drunk drivers is illegal.
A three-judge bench on Friday said the laws introduced by NTSA are inconsistent with the Traffic Act.
The court ordered that they be taken back to Parliament for review.
The decision was reached after a successful petition by Reminisce club on Langata road.
In March 2014, the court ruled that the two cases that sought to abolish the breathalysers be argued together.
Justice Mumbi Ngugi consolidated the first case filed by Richard Ogendo and another by Kariuki Ruitha - proprietor of Reminisce Sports Bar.
Pottermark Enterprises, the company that supplies the gadgets under the Alco-blow brand was also involved as an interested party.
Why street model Lupita NyaKisumo has left Nairobians mesmerized