The move will put pressure on Girija Prasad Koirala, Nepal's prime minister and leading figure in the rival Nepali congress party, to step down and make way for a new government.
"We quit the government to help the process of forming a new government," Pampha Bhusal, women and social welfare minister, said.
"We believe our resignation is enough to pave the way for formation of the new government," she said.
However, the move will not bring about the immediate collapse of the current coalition as the resignations were delivered to the Maoist leader Prachanda and not the prime minister and acting head of state, party officials said.
Koirala is acting as head of state since the Maoist dominated constituent assembly abolished the monarchy last month and this means there is no one to compel him to stand down from his role as prime minister.
He has not yet given a reason for remaining in his position after his party lost the election, but in the two months since he has pushed to be named as president, a post that will be created by the constituent assembly.
Gyanendra, the former king, left the royal palace in the capital Kathmundu on Wednesday to live as a commoner at a former hunting lodge on the edge of the city.