At at least 17 people were also injured the crash that occurred in Kisantu in Kongo-Central province, about 200 kilometers southwest of capital Kinshasa.
At least 27 people were killed after a bus and a truck collided west of the capital, Kinshasa, a Congolese health official said on Tuesday.
The crash occurred in Kisantu in Kongo-Central province, about 200 kilometers southwest of capital Kinshasa.
The city is on the main highway between the capital and the country's Matadi seaport.
Dr Sylvain Yuma with the health ministry says the accident occurred overnight and that excessive speed was to blame.
Yuma says at least 17 people are hurt, six of them seriously. They have been taken to Kinshasa.
A mother and baby are among the dead.
A collision between two trucks in October in a village near Kisantu killed at least 53 people.