"Fifteen dead bodies have been recovered from Gwalichaur village after landslides Thursday night," said police officer Bal Krishna Sharma, from Baglung district 180 kilometres (110 miles) west of Kathmandu
Police expected the death toll to climb, with three people still missing Sharma said.
"Rescue teams have not been able to reach all the four landslide sites because of difficult terrain and weather conditions," he said.
Another five people were killed Thursday night in a landslide in Bartola village in Bajura district, 420 kilometres (262 miles) west of the capital, police official Binod Thapa told AFP.
"Only two bodies have been recovered so far, but we know the other three missing people are dead," Thapa said.
Dozens of people in Nepal die annually in the monsoon, some from landslides, and others from river flooding.