The grisly accident which occurred at 9pm involved several vehicles at the Naivasha junction along the Nakuru- Nairobi highway.
Two of those who died are said to have been tourists.
Naivasha District Hospital Medical Superintendent Dr Joseph Mburu reported that five people died while undergoing treatment at the hospital.
“Ten people were admitted to the hospital last night and five have since been treated and discharged,” he said.
He added that another patient was transferred to a hospital of choice and a second one referred to Kenyatta National Hospital for specialised treatment.
Three survivors of the accident were still undergoing treatment at the hospital and they included two men, and one woman.
They are said to be in a stable condition.
The accident is said to have occurred when a matatu ferrying passengers from Nairobi was hit from behind by a lorry. The matatu then hit another vehicle ahead of it on impact.
According to police statistics, eighty percent of accidents on Kenyan roads are caused by over speeding.
As of September 27, traffic police had recorded 275 deaths from 1,541 road accidents with those dead being 111 pedestrians, 86 passengers and 25 drivers.