A lorry driver died on the spot in a Friday dawn crash at Kinyambu market, Makindu.
The lorry collided head-on with a Nairobi-bound Tahmeed bus on the Nairobi-Mombasa highway.
The driver and conductor of the bus were injured and were take to Makindu Sub-county Hospital for treatment.
None of the passengers in the bus was injured, according to Geoffrey Oderi, deputy Kibwezi police boss, who conmfirmed the collision.
According to Mr Oderi, the lorry was driving on the wrong lane when the smash-up happened.
The accident comes amid intensified calls by Makueni County Commissioner Mohammed Maalim for motorists to be extra careful on roads this Easter holiday.
On Thursday, Mr Maalim met administrators and police officers from the county and reiterated the government's commitment to enforce traffic rules.
"We want to ask trailers to stick to their lanes because they are known for careless overtaking," said Mr Maalim.