Lawyers are voting for their male representative to join the Judicial Service Commission.
Law Society of Kenya says the elections will take place in 28 centres across the country and will be conducted by the Independent Electoral and Boundaries Commission.
Irungu Gathii, Njeru Macharia, Tom Ojienda and Charles Mongare Ongoto are the candidates.
The society said the main tallying centre will be at the LSK Secretariat in Lavington, the exercise having started at 8.30am running through to 5.00pm.
The High Court had cleared Gathii and Ojienda to be on the ballot after dismissing a case challenging their candidature.