The accident occurred in Jyamarung village along the Dhadingbesi-Arughat highway in Dhading district in the west of Kathmandu. The bus with 45 passengers was heading to Dhadingbesi from Aarughat.
Five people died in the accident and 36 others sustained injuries, authorities said.
At least 28 people, who sustained serious injuries, have been ferried to the capital for medical treatment.