Hundreds of Kisumu residents on Friday thronged Kisumu International Airport to welcome Governor Anyang' Nyong'o who has been away for close to two months.
Prof Nyong'o, who underwent a successful hipbone surgery at the University of California Hospital in the US, assured his supporters that he is now fit to resume work.
The governor, who landed at 10am, was received and briefed by top county officials for about 30 minutes before meeting the locals.
"I thank my deputy Dr Mathews Owili, the county executives and the entire Nasa fraternity for their steadfast support for the period that I was out of the country," he said.
He reiterated his commitment to the Nasa leadership and cause headed by the "People's President" Raila Oginga.
The governor's convoy later caused a huge traffic as he made his way through the central business district to ACK St Stephens Cathedral Church in Milimani for a prayer service.
He is also expected address a public rally at Home Kenyatta Grounds.
Prof Nyong'o sought specialised treatment following advice from an orthopaedic surgeon at the Aga Khan University Hospital in Nairobi in February 2017.
The county boss suffered an injury after he was involved in a crash on Kiambu Road as he travelled to Jomo Kenyatta International Airport in November 2016.