Until today, Mutahi Kahiga had served as the devolved unit's Deputy Governor.
Dr Wahome Gakuru passed away in a grisly road accident last week.
Mutahi Kahiga has been sworn in as the fourth governor of Nyeri County to replace Dr Wahome Gakuru who died in a road crash in Murang’a last week.
Until today, he had served as the devolved unit's Deputy Governor.
Mr Mutahi, a former teacher, had earlier sought to reassure those he said were uneasy about his ascension to the helm saying he is up to the task.
“The reason people are uneasy is because I was elected as the Deputy Governor. But Dr Gakuru made his choice when he picked me,” he said.
Dr Gakuru, who passed away in a grisly road accident that is now under investigation, was the second Nyeri County boss to die in office after Nderitu Gachagua who died in a London hospital in February this year.
ICT Cabinet Secretary Joe Mucheru and Former Nyeri Governor Samuel Wamathai were present at Monday's swearing in ceremony.