Police said three children were among the dead in the accident that occurred at Sobea area in Rongai, about seven kilometers from the Salgaa black spot.
According to police, the truck was headed to Nakuru from Eldoret while the matatu was going the opposite direction when they collided.
Survivors in the matatu told police the accident occurred when the driver tried to over the truck at a sharp corner, but police said they were yet to verify the information.
The accident occurred at the same spot where five teenagers died in a car crash on the Christmas Eve of last year, among others which have claimed many lives in the past.
More than 100 people were burnt to death when an oil tanker went up in flames after an accident at the Sachangwan black spot, making the area one of the most dangerous for motorists and pedestrians due to the high number of accidents reported there.