Julius Kipkorir Cheruiyot, a jailbird at Kericho Medium Prison, could not hide his joy after he voted during Tuesday's polls.
Having been in jail for the past 20 years, Mr Cheruiyot has never voted.
"I thank our leaders for passing a law to give us this opportunity so I can elect a leader who I want," said Mr Cheruiyot who is completing his 20-year term for rape in two months.
He is one of the 23 prisoners who are enlisted as voters in the county.
Ishmael Tanui, another voter jailed for 10 years at the facility, also voted the first time.
Mr Tanui made a passionate appeal to Kenyans to maintain peace and elect credible leaders.
"We are grateful for the opportunity given to us by the government to exercise a rare democratic right," said Mr Tanui. "Let us maintain peace because voting is a day's event but our country lasts for a lifetime."
The officer in charge of Kericho Medium Prison, Francis Opondo, lauded the move to allow inmates to vote was a commendable step towards upholding justice.
"For the 27 years I have been working with the prisons, this is a unique provision by the government.
I have visited first world countries and found out that most do not have such privileges," said Mr Opondo.