The volunteers were greeted at Kathmandu airport by U.S. Ambassador Peter W. Bodde and his wife Tanya, the U.S. Embassy said in a report.
The arrival of the volunteers was described as auspicious since this year marks the 50th anniversary of when the Peace Corps first came to the Himalayan state in 1962. Before the program was suspended, more than 4,200 volunteers had served in Nepal.
Bodde said the volunteers have played a special role in the development history of Nepal. He said many Nepali friends and colleagues of his had shared life-changing stories with him about their work.
The new volunteers will be trained for 12 weeks before being sent to three Western region districts of Baglung, Syangja and Parbat to work on food security, sanitation and health projects, the announcement said.
Last Thursday, the U.S. State Department said it had revoked its designation of the country's Communist Party -- the Maoists -- as a terrorist organization. The department said it had determined the Communist Party, which has led Nepal's coalition government, is no longer engaged in terrorist activity that threatens the security of U.S. nationals or U.S. foreign policy.
The party, the department said, has demonstrated "a credible commitment to pursuing the peace and reconciliation process in Nepal."
"Today's delisting does not seek to overlook or forget the party's violent past, but rather looks ahead towards the party's continued engagement in a peaceful, democratic political dialogue in Nepal," the department said.
"This delisting reflects the United States' resolve to keep our terrorism sanctions current and demonstrates that a group need not stay on a terrorist list forever should it demonstrate a credible commitment to pursuing peace and reconciliation."
Citing concern for the volunteers' safety, the Peace Corps left Nepal in September 2004, two years before the Maoist-led insurgency ended with a United Nations-led peace accord. Until then Nepal had been a Hindu kingdom for nearly three centuries. Nepal is now a republic sandwiched between India and China.
The State Department said prior to departing for Nepal, the 20 volunteers participated in a ceremony in their honor in Washington, D.C., attended by Peace Corps Director Aaron Williams, Nepalese Ambassador to the United States Shankar Sharma and others.
"We are pleased that the government of Nepal has invited Peace Corps volunteers to return," Williams said. "Peace Corps has a long and rich history in Nepal and this is an opportunity to continue that fruitful relationship."
Sharma said the Nepalese people have always admired and appreciated the contribution and friendliness of Peace Corps volunteers and that the new volunteers "will gain a lifetime positive experience in working with the villagers of Nepal."